1 MDISPLAY 
Display an image on any workstation running X

SYNOPSIS

  $ mdisplay [ options ...] file [ [ options ...] file ...]

2 DESCRIPTION
Display is a machine architecture independent image processing
and display program.  It can display an image on any workstation
screen running an X server.  Display can read and write many of
the more popular image formats (e.g. JPEG, TIFF, PNM, Photo CD, etc.).
With display, you can perform these functions on an image:
 
    o load an image from a file
    o display the next image
    o display the former image
    o display a sequence of images as a slide show
    o write the image to a file
    o print the image to a Postscript printer
    o delete the image file
    o create a Visual Image Directory
    o select the image to display by its thumbnail rather than name
    o copy a region of the image
    o paste a region to the image
    o undo last image transformation
    o half the image size
    o double the image size
    o resize the image
    o restore the image to its original size
    o refresh the image
    o crop the image
    o cut the image
    o flop image in the horizontal direction
    o flip image in the vertical direction
    o rotate the image 90 degrees clockwise
    o rotate the image 90 degrees counter-clockwise
    o rotate the image
    o shear the image
    o trim the image edges
    o invert the colors of the image
    o vary the color brightness
    o vary the color saturation
    o vary the image hue
    o gamma correct the image
    o sharpen the image contrast
    o dull the image contrast
    o perform histogram equalization on the image
    o perform histogram normalization on the image
    o negate the image colors
    o convert the image to grayscale
    o set the maximum number of unique colors in the image
    o reduce the speckles within an image
    o eliminate peak noise from an image
    o detect edges within the image
    o emboss an image
    o oil paint an image
    o segment the image by color
    o annotate the image with text
    o draw on the image
    o edit an image pixel color
    o edit the image matte information
    o composite an image with another
    o add a border to the image
    o surround image with an ornamental border
    o add an image comment
    o apply image processing techniques to a region of interest
    o display information about the image
    o show a histogram of the image
    o display image to background of a window
    o set user preferences
    o display information about this program
    o discard all images and exit program
    o change the level of magnification
    o display images specified by a World Wide Web (WWW) uniform 
      resource locator (URL)

2 EXAMPLES
To scale an image of a cockatoo to exactly 640 pixels in width and 480
pixels in height and position the window at location (200,200), use:

  $ mdisplay -geometry 640x480+200+200! cockatoo.miff
 
To display an image of a cockatoo without a border centered on a
backdrop, use:
 
  $ mdisplay +borderwidth -backdrop cockatoo.miff
 
To tile a slate texture onto the root window, use:
 
  $ mdisplay -size 1280x1024 -window root slate.png

To display a visual image directory of all your JPEG images, use:
 
  $ mdisplay 'vid:*.jpg'
 
To display a MAP image that is 640 pixels in width and 480
pixels in height with 256 colors, use:
 
  $ mdisplay -size 640x480+256 cockatoo.map
 
To display an image of a cockatoo specified with a World Wide Web (WWW)
uniform resource locator (URL), use
 
     display ftp://wizards.dupont.com/images/cockatoo.jpg

2 OPTIONS

    -annotate string
annotate an image with text.
 
Use this option to annotate an image with text.  Optionally you can
include the image filename, type, width, height, or scene number by
embedding special format characters.  Embed %f for filename,
%m for magick, %w for width, %h for height, %s
for scene number, or \n for newline.  For example,
 
     -annotate "%m:%f %wx%h"
 
annotates the image with MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.
 
If the first character of string is @, the text is read
from a file titled by the remaining characters in the string.
 
You can set the text position, font, font color, and bounding box color with
-geometry, -font, -pen, and -box respectively.
Options are processed in command line order so be sure to use -geometry,
-font, -pen or -box before the -annotate option.

    -backdrop
display the image centered on a backdrop.

This backdrop covers the entire workstation screen and is useful for
hiding other X window activity while viewing the image.   The color of
the backdrop is specified as the background color.  Refer to X
RESOURCES for details.
 
    -border <width>x<height>
surround the image with a border or color.  See X(1) for details
about the geometry specification.

The color of the border is obtained from the X server and is defined as
bordercolor (class borderColor).  See X(1) for details.
 
    -box color
set the color of the annotation bounding box.  See -annotate or
for further details.
 
See X(1) for details about the color specification.
 
    -colormap type
the type of colormap: Shared or Private.

This option only applies when the default X server visual is PseudoColor
or GrayScale.  Refer to -visual for more details.  By default, a shared
colormap is allocated.  The image shares colors with other X clients. 
Some image colors could be approximated, therefore your image may look
very different than intended.  Choose Private and the image colors
appear exactly as they are defined.  However, other clients may go
technicolor when the image colormap is installed.
 
    -colors value
preferred number of colors in the image.

The actual number of colors in the image may be less than your request,
but never more.  Note, this is a color reduction option.  Images with
less unique colors than specified with this option will remain unchanged.
Refer to quantize(9) for more details.

Note, options -dither, -colorspace, and -treedepth affect
the color reduction algorithm.
 
    -colorspace value
the type of colorspace: GRAY, OHTA, RGB, XYZ,
YCbCr, YIQ, YPbPr, or YUV.

Color reduction, by default, takes place in the RGB color space.
Empirical evidence suggests that distances in color spaces such as YUV
or YIQ correspond to perceptual color differences more closely
than do distances in RGB space.  These color spaces may give better
results when color reducing an image.  Refer to quantize(9) for
more details.

The -colors or -monochrome option is required for this option
to take effect.
 
    -comment string
annotate an image with a comment.

By default, each image is commented with its file name.  Use this
option to assign a specific comment to the image.  Optionally you can
include the image filename, type, width, height, or scene number by
embedding special format characters.  Embed %f for filename,
%m for magick, %w for width, %h for height, %s
for scene number, or \n for newline.  For example,
 
     -comment "%m:%f %wx%h"
 
produces an image comment of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.

If the first character of string is @, the image comment is read
from a file titled by the remaining characters in the string.
 
    -compress type
the type of image compression: Zlib or RunlengthEncoded.

Use this option with -write to specify the the type of image
compression.  See miff(5) for details.

Specify +compress to store the binary image in an uncompressed format.
The default is the compression type of the specified image file.
 
    -contrast
enhance or reduce the image contrast.

This option enhances the intensity differences between the
lighter and darker elements of the image.  Use -contrast to
enhance the image or +contrast to reduce the image contrast.
 
    -crop <width>{%}x<height>{%}{+-}<x offset>{+-}<y offset>
preferred size and location of the cropped image.  See X(1) for details
about the geometry specification.

To specify a percentage width or height instead, append %.  For example
to crop the image by ten percent on all sides of the image, use
-crop 10%.

Use cropping to apply image processing options to, or display, a
particular area of an image.  Use -crop 0x0 to remove edges that are
the background color.

The equivalent X resource for this option is cropGeometry
(class CropGeometry).  See X RESOURCES for details.
 
    -delay seconds
display the next image after pausing.

This option is useful when viewing several images in sequence.  Each
image will display and wait the number of seconds specified before the
next image is displayed.  The default is to display the image
and wait until you choose to display the next image or terminate the
program.
 
    -density <width>x<height>
vertical and horizontal resolution in pixels of the image.

This option specifies an image density when decoding a Postscript or Portable
Document page.  The default is the same as the resolution of your X server
(see xdpyinfo(1)).
 
    -despeckle
reduce the speckles within an image.
 
    -display host:display[.screen]
specifies the X server to contact; see X(1).
 
    -dither
apply Floyd/Steinberg error diffusion to the image.

The basic strategy of dithering is to trade intensity resolution for
spatial resolution by averaging the intensities of several neighboring
pixels.  Images which suffer from severe contouring when reducing colors
can be improved with this option.

The -colors or -monochrome option is required
for this option to take effect.
 
    -enhance
apply a digital filter to enhance a noisy image.
 
    -equalize
perform histogram equalization to the image.
 
    -flip
create a "mirror image" by reflecting the image scanlines in the vertical
direction.
 
    -flop
create a "mirror image" by reflecting the image scanlines in the horizontal
direction.
 
    -frame <width>x<height>+<outer bevel width>+<inner bevel width>
surround the image with an an ornamental border.  See X(1) for details
about the geometry specification.

The color of the border is specified with the -mattecolor command line
option.
 
    -gamma value
level of gamma correction.

The same color image displayed on two different workstations may look
different due to differences in the display monitor.  Use gamma
correction to adjust for this color difference.  Reasonable values
extend from 0.8 to 2.3.

You can apply separate gamma values to the red, green, and blue
channels of the image with a gamma value list delineated with commas
(i.e. 1.7,2.3,1.2).
 
    -geometry <width>{%}x<height>{%}{+-}<x offset>{+-}<y offset>{!}{<}{>}
preferred size and location of the Image window.  See X(1) for details
about the geometry specification.  By default, the window size is the image
size and the location is chosen by you when it is mapped.

By default, the width and height are maximum values.  That is, the
image is expanded or contracted to fit the width and height value while
maintaining the aspect ratio of the image.  Append an exclamation point
to the geometry to force the image size to exactly the size you
specify.  For example, if you specify 640x480! the image width is
set to 640 pixels and height to 480.  If only one factor is
specified, both the width and height assume the value.

To specify a percentage width or height instead, append %.  The
image size is multiplied by the width and height percentages to obtain
the final image dimensions.  To increase the size of an image, use a
value greater than 100 (e.g. 125%).  To decrease an image's size, use a
percentage less than 100.

Use < to change the dimensions of the image only
if its size exceeds the geometry specification.  > resizes
the image only if its dimensions is less than the geometry
specification.  For example, if you specify 640x480> and the
image size is 512x512, the image size does not change.  However, if
the image is 1024x1024, it is resized to 640x480.

When displaying an image on an X server, <x offset> and
<y offset> is relative to the root window.

The equivalent X resource for this option is geometry
(class Geometry).  See X RESOURCES for details.
 
    -interlace type
the type of interlacing scheme: NONE, LINE, or PLANE.

This option is used to specify the type of interlacing scheme for raw
image formats such as RGB or YUV.  NONE means do not
interlace (RGBRGBRGBRGBRGBRGB...), LINE uses scanline
interlacing (RRR...GGG...BBB...RRR...GGG...BBB...), and PLANE uses
plane interlacing (RRRRRR...GGGGGG...BBBBBB...).

Use LINE, or PLANE to create an interlaced GIF or progressive
JPEG image.
 
    -immutable
displayed image cannot be modified",
 
    -label name
assign a label to an image.

Use this option to assign a specific label to the image.  Optionally
you can include the image filename, type, width, height, or scene
number in the label by embedding special format characters.   Embed
%f for filename, %m for magick, %w for width,
%h for height, or %s for scene number, or \n for newline.
For example,
 
     -label "%m:%f %wx%h"
 
produces an image label of MIFF:bird.miff 512x480 for an image
titled bird.miff and whose width is 512 and height is 480.

If the first character of string is @, the image label is read
from a file titled by the remaining characters in the string.

When converting to Postscript, use this option to specify a header string
to print above the image.
 
    -map type
display image using this Standard Colormap type.

Choose from these Standard Colormap types:
 
    best
    default
    gray
    red
    green
    blue
 
The X server must support the Standard Colormap you choose, otherwise an
error occurs.  Use list as the type and display(1) searches
the list of colormap types in top-to-bottom order until one is located. See
xstdcmap(1) for one way of creating Standard Colormaps.
 
    -matte
store matte channel if the image has one.
 
    -modulate value
vary the brightness, saturation, and hue of an image.

Specify the percent change in brightness, the color saturation, and the hue
separated by commas.  For example, to increase the color brightness
by 20% and decrease the color saturation by 10% and leave the hue
unchanged, use: -modulate 20,-10.
 
    -monochrome
transform the image to black and white.
 
    -negate
apply color inversion to image.

The red, green, and blue intensities of an image are negated.
 
    -noise
reduce the noise in an image with a noise peak elimination filter.

The principal function of noise peak elimination filter is to smooth
the objects within an image without losing edge information and without
creating undesired structures.  The central idea of the algorithm is to
replace a pixel with its next neighbor in value within a 3 x 3 window,
if this pixel has been found to be noise.  A pixel is defined as noise
if and only if this pixel is a maximum or minimum within the 3 x 3 window.
 
    -normalize
transform image to span the full range of color values.

This is a contrast enhancement technique.
 
    -opaque color
change this color to the pen color within the image.  See -pen for
more details.
 
    -page <width>x<height>{+-}<x offset>{+-}<y offset>
size and location of the Postscript page.

Use this option to specify the dimensions of the Postscript page in
pixels per inch or a TEXT page in pixels.  The default for a Postscript
page is to center the image on a letter page 612 by 792 pixels. The
margins are 1/2" (i.e.  612x792+42+42).  Other common sizes are:
 
    Letter      612x 792
    Tabloid     792x1224
    Ledger     1224x 792
    Legal       612x1008
    Statement   396x 612
    Executive   540x 720
    A3          842x1190
    A4          595x 842
    A5          420x 595
    B4          729x1032
    B5          516x 729
    Folio       612x 936
    Quarto      610x 780
    10x14       720x1008
 
For convenience you can specify the page size by media (e.g. A4, Ledger, etc.).

The page geometry is relative to the vertical and horizontal density of the
Postscript page.  See -density for details.

The default page dimensions for a TEXT image is 612x792.
 
    -pen color
set the color of the font or opaque color.  See -annotate or
-opaque for further details.
 
See X(1) for details about the color specification.
 
    -quality value
JPEG quality setting.

Quality is 0 (worst) to 100 (best). The default is 75.
 
    -raise <bevel width>
lighten or darken image edges to create a 3-D effect.
 
Bevel width is the width of an edge.  Use -raise to create a
raised effect, otherwise use +raise.
 
    -roll {+-}<x offset>{+-}<y offset>
roll an image vertically or horizontally.  See X(1) for details
about the geometry specification.

A negative x offset rolls the image left-to-right.  A negative
y offset rolls the image top-to-bottom.
 
    -rotate degrees
apply Paeth image rotation to the image.

Empty triangles left over from rotating the image are filled with
the color defined as bordercolor (class borderColor).
See X(1) for details.
 
    -sample geometry
scale image with pixel sampling.  See -geometry for details
about the geometry specification.
 
    -scene value
image scene number.

Use this option to specify an image sequence with a single filename.  See
the discussion of file below for details.
 
    -sharpen factor
sharpen an image.  Specify factor as the percent enhancement
(0.0 - 99.9%).
 
    -shear <x degrees>x<y degrees>
shear the image along the X or Y axis by a positive or negative shear angle.

Shearing slides one edge of an image along the X or Y axis, creating a
parallelogram.  An X direction shear slides an edge along the X axis,
while a Y direction shear slides an edge along the Y axis.  The amount
of the shear is controlled by a shear angle.  For X direction shears,
x degrees> is measured relative to the Y axis, and similarly, for
Y direction shears y degrees is measured relative to the X axis.

Empty triangles left over from shearing the image are filled with
the color defined as bordercolor (class borderColor).
See X(1) for details.
 
    -size <width>{%}x<height>{%}+<offset>
width and height of the image.

Use this option to specify the width and height of raw images whose
dimensions are unknown such as GRAY, RGB, or CMYK.
In addition to width and height, use -size to skip any header
information in the image or tell the number of colors in a MAP
image file, (e.g. -size 640x512+256).

For Photo CD images, choose from these sizes:
 
     192x128
     384x256
     768x512
    1536x1024
    3072x2048
  
Finally, use this option to choose a particular resolution layer of a JBIG
image (e.g. -size 1024x768).
 
    -texture filename
name of texture to tile onto the image background.
 
    -transparency color
make this color transparent within the image.
 
    -treedepth value
Normally, this integer value is zero or one.  A zero or one tells
display to choose a optimal tree depth for the color reduction
algorithm.

An optimal depth generally allows the best representation of the source
image with the fastest computational speed and the least amount of
memory.  However, the default depth is inappropriate for some images.
To assure the best representation, try values between 2 and 8 for this
parameter.  Refer to quantize(9) for more details.

The -colors or -monochrome option is required
for this option to take effect.
 
    -update seconds
detect when image file is modified and redisplay.

Suppose that while you are displaying an image the file that is
currently displayed is over-written.  display will automatically
detect that the input file has been changed and update the displayed
image accordingly.
 
   -verbose
print detailed information about the image.

This information is printed: image scene number;  image name;  image
size; the image class (DirectClass or PseudoClass);  the total
number of unique colors;  and the number of seconds to read and
transform the image.  Refer to miff(5) for a description of
the image class.

If -colors is also specified, the total unique colors in the image
and color reduction error values are printed.  Refer to quantize(9)
for a description of these values.
 
    -visual type
display image using this visual type.

Choose from these visual classes:
 
    StaticGray
    GrayScale
    StaticColor
    PseudoColor
    TrueColor
    DirectColor
    default
    visual id
 
The X server must support the visual you choose, otherwise an error occurs.
If a visual is not specified, the visual class that can display the most
simultaneous colors on the default X server screen is chosen.
 
    -window id
set the background pixmap of this window to the image.

id can be a window id or name.  Specify root to select X's root
window as the target window.

By default the image is tiled onto the background of the target
window.   If -backdrop or -geometry are specified, the
image is surrounded by the background color.  Refer to X
RESOURCES for details.

The image will not display on the root window if the image has more
unique colors than the target window colormap allows.  Use
-colors to reduce the number of colors.

    -window_group id
exit program when this window id is destroyed.

id can be a window id or name.
 
    -write filename
write image to a file.

If file already exists, you will be prompted as to whether
it should be overwritten.

By default, the image is written in the format that it was read in as.
To specify a particular image format, prefix file with the image type
and a colon (i.e. ps:image) or specify the image type as the filename
suffix (i.e. image.ps).  See convert(1) for a list of valid image
formats.  Specify file as - for standard output.  If file has the
extension .Z or .gz, the file size is compressed using with compress or
gzip respectively.  Precede the image file name | to pipe to a system
command. If file already exists, you will be prompted as to whether it
should be overwritten.

Use -compress to specify the type of image compression.

The equivalent X resource for this option is writeFilename
(class WriteFilename).  See X RESOURCES for details.
 
In addition to those listed above, you can specify these standard X
resources as command line options:  -background, -bordercolor,
-borderwidth, -font, -foreground, -iconGeometry, -iconic, -mattecolor,
-name, or -title.  See X RESOURCES for details.
 
Options are processed in command line order.
Any option you specify on the command line remains in effect until it is
explicitly changed by specifying the option again with a different effect.
For example to display two images, the first with 32 colors, and the
second with only 16 colors, use:
 
 $ mdisplay -colors 32 cockatoo.miff -colors 16 macaw.miff
 
Change - to + in any option above to reverse its effect.
For example, specify +matte to store the image without its matte
channel.
 
By default, the image format is determined by its magic number. To
specify a particular image format, precede the filename with an image
format name and a colon (i.e. ps:image) or specify the image type as
the filename suffix (i.e. image.ps).  See convert(1) for a list
of valid image formats.
 
When you specify X as your image type, the filename has special
meaning.  It specifies an X window by id, name, or root.  If no
filename is specified, the window is selected by clicking the mouse in
the desired window.
 
Specify file as - for standard input.  If file has
the extension .Z or .gz, the file is uncompressed with
uncompress or gunzip respectively.  Precede the image file
name | to pipe from a system command.
 
Use an optional index enclosed in brackets after a file name to specify
a desired subimage of a multi-resolution image format like Photo CD
(e.g. img0001.pcd[4]) or a range for MPEG images (e.g. video.mpg[50-75]).
 
Single images are read with the filename you specify.  Alternatively,
you can display an image sequence with a single filename.  Define the
range of the image sequence with -scene.  Each image in the
range is read with the filename followed by a period (.)
and the scene number.  You can change this behavior by embedding a
printf format specification in the file name.  For example,
 
        -scene 0-9 image%02d.miff
 
displays files image00.miff, image01.miff, through image09.miff.

2 BUTTONS
The effects of each button press is described below.  Three buttons are
required.  If you have a two button mouse, button 1 and 3 are returned.
Press ALT and button 3 to simulate button 2.
 
    1
Press this button to map or unmap the Command widget.  See
the next section for more information about the Command widget.
 
    2
Press and drag to define a region of the image to magnify.
 
    3
Press and drag to choose from a select set of display(1) commands.
This button behaves differently if the image being displayed is a visual
image directory.  Here, choose a particular tile of the directory and press
this button and drag to select a command from a pop-up menu.  Choose from
these menu items:
 
    Load
    Delete
 
If you choose Delete, the image represented by the tile is
deleted.  Otherwise, it is displayed.  To return to the visual image
directory, choose Next from the Command widget (refer to
COMMAND WIDGET).  See montage(1) and miff(5) for more
details.

2 COMMAND_WIDGET
The Command widget lists a number of sub-menus and commands.  They are
 
    File
      Load...
      Next
      Former
      Select...
      Save...
      Print...
      Delete...
      Canvas...
      Visual Directory...
      Quit
    Edit
      Cut
      Copy
      Paste
      Undo
    View
      Half Size
      Original Size
      Double Size
      Resize...
      Apply
      Refresh
      Restore
    Transform
      Crop
      Chop
      Flop
      Flip
      Rotate Right
      Rotate Left
      Rotate...
      Shear...
      Trim Edges
    Enhance
      Hue...
      Saturation...
      Brightness...
      Gamma...
      Spiff...
      Dull
      Equalize
      Normalize
      Negate
      Grayscale
      Quantize...
    Effects
      Despeckle
      Peak Noise
      Sharpen...
      Blur...
      Edge Detect
      Emboss
      Oil Painting
      Raise...
      Segment...
    Image Edit
      Annotate
      Draw
      Color
      Matte
      Composite...
      Add Border...
      Add Frame...
      Comment
      Region of Interest
    Miscellany
      Image Info
      Zoom Image
      Show Histogram
      Background...
      Slide Show
      Preferences...
    Help
      Help
      Browse Documentation
      About Display
 
Menu items with a indented triangle have a sub-menu.  They are
represented above as the indented items.  To access a sub-menu item,
move the pointer to the appropriate menu and press a button and drag.
When you find the desired sub-menu item, release the button and the
command is executed.  Move the pointer away from the sub-menu if you
decide not to execute a particular command.

2 KEYBOARD_ACCELERATORS
Accelerators are one or two key presses that effect a particular command.
The keyboard accelerators that display(1) understands is:

(Under OpenVMS, F20 key has ESCape value)
 
    l
Press to load an image from a file.

Refer to IMAGE LOADING for more details.
 
    n
Press to display the next image.

If the image is a multi-paged document such as a Postscript document, you
can skip ahead several pages by preceeding this command with a number.  
For example to display the fourth page beyond the current page,
press 4n.
 
    f
Press to display the former image.

If the image is a multi-paged document such as a Postscript document, you
can skip behind several pages by preceeding this command with a number.  
For example to display the fourth page preceeding the current page,
press 4n.
 
    F2
Press to select an image from the command line.
 
    s
Press to save the image to a file.
 
    p
Press to print the image to a Postscript printer.
 
    delete
Press to delete an image file.
 
    C
Press to create a blank canvas.
 
    V
Press to create a Visual Image Directory.

Refer to VISUAL IMAGE DIRECTORY for more details.
 
    q
Press to discard all images and exit program.
 
    F3
Press to cut a region of the image.

Refer to IMAGE CUTTING for more details.
 
    F4
Press to copy a region of the image.

Refer to IMAGE COPYING for more details.
 
    F5
Press to paste a region to the image.

Refer to IMAGE PASTING for more details.
 
    u
Press to undo last image transformation.
 
    <
Press to half the image size.
 
    o
Press to return to the original image size.
 
    >
Press to double the image size.
 
    %
Press to resize the image to a width and height you specify.
 
    A
Press to make any image transformations permanent.

By default, any image size transformations are applied to the
original image to create the image displayed on the X server.  However, the
transformations are not permanent (i.e. the original image does not change
size only the X image does).  For example, if you press > the X image
will appear to double in size, but the orginal image will in fact remain the
same size.  To force the original image to double in size, press >
followed by A.
 
    @
Press to refresh the Image window.
 
    r
Press to restore the image to its original size.
 
    [
Press to crop the image.

Refer to IMAGE CROPPING for more details.
 
    ]
Press to chop the image.

Refer to IMAGE CHOPPING for more details.
 
    |
Press to flop image in the horizontal direction.
 
    -
Press to flip image in the vertical direction.
 
    /
Press to rotate the image 90 degrees clockwise.
 
   \
Press to rotate the image 90 degrees counter-clockwise.
 
    *
Press to rotate the image the number of degrees you specify.

Refer to IMAGE ROTATION for more details.
 
    F6
Press to shear the image the number of degrees you specify.
 
    t
Press to trim the image edges.
 
    F7
Press to vary the color hue.
 
    F8
Press to vary the color saturation.
 
    F9
Press to vary the image brightness.
 
    g
Press to gamma correct the image.
 
    F10
Press to spiff up the image contrast.
 
    F11
Press to dull the image contrast.
 
    =
Press to perform histogram equalization on the image.
 
    N
Press to perform histogram normalization on the image.
 
    ~
Press to negate the colors of the image.
 
    G
Press to convert the image colors to gray.
 
    #
Press to set the maximum number of unique colors in the image.
 
    D
Press to reduce the speckles in an image.
 
    P
Press to eliminate peak noise from an image.
 
    S
Press to sharpen an image.
 
    B
Press to blur image an image.
 
    E
Press to detect edges within an image.
 
    M
Press to emboss an image.
 
    O
Press to oil paint an image.
 
    ^
Press to lighten or darken image edges to create a 3-D effect.
 
    Z
Press to segment the image by color.
 
    R
Press to apply an image processing technique to a region of interest.

Refer to REGION OF INTEREST for more details.
 
    a
Press to annotate the image with text.

Refer to IMAGE ANNOTATION for more details.
 
    d
Press to draw a line on the image.

Refer to IMAGE DRAWING for more details.
 
    C
Press to edit an image pixel color.

Refer to COLOR EDITING for more details.
 
    m
Press to edit the image matte information.

Refer to MATTE EDITING for more details.
 
    x
Press to composite the image with another.

Refer to IMAGE COMPOSITING for more details.
 
    a
Press to add a border to the image.
 
    F
Press to add a ornamental frame to the image.
 
    !
Press to add an image comment.
 
    i
Press to display information about the image.
 
    z
Press to map the zoom image window.
 
    H
Press to show a histogram of the image.
 
    }
Press to display image to background of a window.
 
    ,
Press to display the next image after pausing.
 
    F12
Press to set user preferences.

Refer to USER PREFERENCES for more details.
 
    h
Press to display helpful information about display(1).

Function keys HELP or F1 are synonymous with the h key.
 
    Find
Press to browse documentation about ImageMagick.
 
    v
Press to display the version number of display(1).
 
    1-9
Press to change the level of magnification.
 
Use the arrow keys to move the image one pixel up, down, left, or right within
the magnify window.  Be sure to first map the magnify window by pressing
button 2.

Press ALT and one of the arrow keys to trim off one pixel from
any side of the image.

2 X_RESOURCES
Display options can appear on the command line or in your X
resource file.  Options on the command line supersede values specified
in your X resource file.  See X(1) for more information on X
resources.

Most display options have a corresponding X resource.  In addition,
display uses the following X resources:
 
   background (class Background)
Specifies the preferred color to use for the Image window background.  The
default is #ccc.
 
   borderColor (class BorderColor)
Specifies the preferred color to use for the Image window border.  The
default is black.
 
   borderWidth (class BorderWidth)
Specifies the width in pixels of the Image window border.  The default is 2.
 
   confirmExit (class ConfirmExit)
Whether Display will pop up a dialog box to confirm exiting the
program when the Quit menu option is chosen. Default is False. 
 
   displayGamma (class displayGamma)
Specifies the gamma of your X server.
The default is 2.2.
 
   editorCommand (class editorCommand)
Specifies the name of the preferred editor when editing image comments.
The default is xterm -title "Edit Image Comment" -e vi %s.
 
   font (class FontList)
Specifies the name of the preferred font to use in normal formatted
text.  The default is 14 point Helvetica.
 
   font[1-9] (class Font[1-9])
Specifies the name of the preferred font to use when annotating the
Image window with text.  The default fonts are fixed,
variable, 5x8, 6x10, 7x13bold, 8x13bold,
9x15bold, 10x20, and 12x24.  Refer to IMAGE
ANNOTATION for more details.
 
   foreground (class Foreground)
Specifies the preferred color to use for text within the Image window.  The
default is black.
 
   gammaCorrect (class gammaCorrect)
This resource, if true, will lighten or darken an image of known gamma to match
the gamma of the display (see resource displayGamma).
The default is True.
 
   geometry (class Geometry)
Specifies the preferred size and position of the image window.
It is not necessarily obeyed by all window managers.
 
   iconGeometry (class IconGeometry)
Specifies the preferred size and position of the application when
iconified.  It is not necessarily obeyed by all window managers.
 
   iconic (class Iconic)
This resource indicates that you would prefer that the application's
windows initially not be visible as if the windows had be immediately
iconified by you.  Window managers may choose not to honor the
application's request.
 
   magnify (class Magnify)
specifies an integral factor by which the image should be enlarged.  The
default is 3.

This value only affects the magnification window which is invoked with
button number 3 after the image is displayed.  Refer to BUTTONS
for more details.
 
   matteColor (class MatteColor)
Specify the color of windows.  It is used for the backgrounds of
windows, menus, and notices.  A 3D  effect  is achieved  by
using highlight and shadow colors derived from this color.  Default
value: #ccc.
 
   name (class Name)
This resource specifies the name under which resources for the
application should be found.  This resource is useful in shell aliases to
distinguish between invocations of an application, without resorting to
creating links to alter the executable file name.  The default is the
application name.
 
   pen[1-9] (class Pen[1-9])
Specifies the color of the preferred font to use when annotating the
Image window with text.  The default colors are black,
blue, green, cyan, gray, red,
magenta, yellow, and white.  Refer to IMAGE
ANNOTATION for more details.
 
   printCommand (class PrintCommand)
This command is executed whenever Print is issued (see BUTTONS.
In general, it is the command to print Postscript to your printer.
Default value: lpr %s.
 
   sharedMemory (class SharedMemory)
This resource specifies whether display should attempt use shared memory
for pixmaps.  ImageMagick must be compiled with shared memory support,
and the display must support the MIT-SHM extension.  Otherwise, this
resource is ignored.  The default is True.
 
   textFont (class textFont)
Specifies the name of the preferred font to use in fixed (typewriter style)
formatted text.  The default is 14 point Courier.
 
   title (class Title)
This resource specifies the title to be used for the Image window.  This
information is sometimes used by a window manager to provide a
header identifying the window.  The default is the image file name.
 
   usePixmap (class UsePixmap)
Images are maintained as a XImage by default.  Set this resource to True
to utilize a server Pixmap instead.  This option is useful if your image
exceeds the dimensions of your server screen and you intend to pan the
image.  Panning is much faster with Pixmaps than with a XImage.
Pixmaps are considered a precious resource, use them with discretion.
 
To set the geometry of the Magnify or Pan or window, use the
geometry resource.  For example, to set the Pan window geometry
to 256x256, use:
 
    display.pan.geometry: 256x256
 
2 IMAGE_LOADING
To select an image to display, choose Load of the File sub-menu
from the Command widget.  A file browser is displayed.  To choose a
particular image file, move the pointer to the filename and press any
button.  The filename is copied to the text window.  Next, press
Load or press the RETURN key.  Alternatively, you can type the
image file name directly into the text window.  To descend directories,
choose a directory name and press the button twice quickly.  A scrollbar
allows a large list of filenames to be moved through the viewing area if
it exceeds the size of the list area.
 
You can trim the list of file names by using shell globbing characters.
For example, type *.jpg to list only files that end with .jpg.
 
To select your image from the X server screen instead of from a file,
Choose Grab of the Load widget.

2 VISUAL_IMAGE_DIRECTORY
To create a Visual Image Directory, choose Visual Directory of
the File sub-menu from the Command widget.  A file browser is
displayed.  To create a Visual Image Directory from all the images in
the current directory, press Directory or press the RETURN key.
Alternatively, you can select a set of image names by using shell
globbing characters.  For example, type *.jpg to include only
files that end with .jpg.  To descend directories, choose a
directory name and press the button twice quickly.  A scrollbar allows
a large list of filenames to be moved through the viewing area if it
exceeds the size of the list area.
 
After you select a set of files, they are turned into thumbnails and
tiled onto a single image.  Now move the pointer to a particular
thumbnail and press button 3 and drag.  Finally, select Load.  The
image represented by the thumbnail is displayed at its full size.
Choose Next from the File sub-menu of the Command widget to
return to the Visual Image Directory.

2 IMAGE_CUTTING
Note that cut information for Image window is not retained for
colormapped X server visuals (e.g. StaticColor,
StaticColor, GrayScale, PseudoColor).  Correct
cutting behavior may require a TrueColor or DirectColor
visual or a Standard Colormap.
 
To begin, press choose Cut of the Edit sub-menu from
the Command widget (see COMMAND WIDGET).  Alternatively, press F3
in the Image window (see KEYBOARD ACCELERATORS).
 
A small window appears showing the location of the cursor in the image
window.  You are now in cut mode.  In cut mode, the Command
widget has these options:
 
    Help
    Dismiss
 
To define a cut region, press button 1 and drag.  The cut
region is defined by a highlighted rectangle that expands or contracts
as it follows the pointer.  Once you are satisfied with the cut
region, release the button.  You are now in rectify mode.
In rectify mode, the Command widget has these options:
 
    Cut
    Help
    Dismiss
 
You can make adjustments by moving the pointer to one of the cut
rectangle corners, pressing a button, and dragging.
Finally, press Cut to commit your copy region.  To exit without
cutting the image, press Dismiss.

2 IMAGE_COPYING
To begin, press choose Copy of the Edit sub-menu from
the Command widget (see COMMAND WIDGET).  Alternatively, press F4
in the Image window (see KEYBOARD ACCELERATORS).
 
A small window appears showing the location of the cursor in the image
window.  You are now in copy mode.  In copy mode, the Command
widget has these options:
 
    Help
    Dismiss
 
To define a copy region, press button 1 and drag.  The copy
region is defined by a highlighted rectangle that expands or contracts
as it follows the pointer.  Once you are satisfied with the copy
region, release the button.  You are now in rectify mode.
In rectify mode, the Command widget has these options:
 
    Copy
    Help
    Dismiss
 
You can make adjustments by moving the pointer to one of the copy
rectangle corners, pressing a button, and dragging.
Finally, press Copy to commit your copy region.  To exit without
copying the image, press Dismiss.

2 IMAGE_PASTING
To begin, press choose Paste of the Edit sub-menu from
the Command widget (see COMMAND WIDGET).  Alternatively, press F5
in the Image window (see KEYBOARD ACCELERATORS).
 
A small window appears showing the location of the cursor in the image
window. You are now in Paste mode.  To exit immediately,
press Dismiss.  In Paste mode, the Command widget has these
options:
 
    Operators
      over
      in
      out
      atop
      xor
      plus
      minus
      add
      subtract
      difference
      replace
    Help
    Dismiss
 
Choose a composite operation from the Operators sub-menu of the
Command widget.  How each operator behaves is described below.
Image window is the image currently displayed on your X server and
image is the image obtained with the File Browser widget.
 
 
   over
The result is the union of the two image shapes, with image
obscuring Image window in the region of overlap.
 
   in
The result is simply image cut by the shape of image
window.  None of the image data of Image window is in the
result.
 
   out
The resulting image is image with the shape of Image window
cut out.
 
   atop
The result is the same shape as image Image window, with
image obscuring Image window where the image shapes
overlap.  Note this differs from over because the portion of
image outside Image window's shape does not appear in the
result.
 
   xor
The result is the image data from both image and Image window
that is outside the overlap region.  The overlap region is blank.
 
   plus
The result is just the sum of the image data.  Output values are
cropped to 255 (no overflow).  This operation is independent
of the matte channels.
 
   minus
The result of image - Image window, with underflow cropped
to zero.  The matte channel is ignored (set to 255, full coverage).
 
   add
The result of image + Image window, with overflow wrapping
around (mod 256).
 
   subtract
The result of image - Image window, with underflow wrapping
around (mod 256).  The add and subtract operators can
be used to perform reversible transformations.
 
   difference
The result of abs(image - Image window).  This is useful
for comparing two very similar images.
 
   replace
The resulting image is Image window replaced with image.
Here the matte information is ignored.
 
The image compositor requires a matte, or alpha channel in the image
for some operations.  This extra channel usually defines a mask which
represents a sort of a cookie-cutter for the image.  This is the case
when matte is 255 (full coverage) for pixels inside the shape, zero
outside, and between zero and 255 on the boundary.  If image does
not have a matte channel, it is initialized with 0 for any pixel
matching in color to pixel location (0,0), otherwise 255.  See
MATTE EDITING for a method of defining a matte channel.
 
Note that matte information for Image window is not retained for
colormapped X server visuals (e.g. StaticColor,
StaticColor, GrayScale, PseudoColor).  Correct
compositing behavior may require a TrueColor or DirectColor
visual or a Standard Colormap.
 
Choosing a composite operator is optional.  The default operator is
replace.  However, you must choose a location to composite your image
and press a button.  Press and hold the button before releasing and an
outline of the image will appear to help you identify your location.
 
The actual colors of the pasted image is saved.  However, the color
that appears in Image window may be different.  For example, on a
monochrome screen Image window will appear black or white even
though your pasted image may have many colors.  If the image is
saved to a file it is written with the correct colors.  To assure the
correct colors are saved in the final image, any PseudoClass
image is promoted to DirectClass (see miff(5)).  To force a
PseudoClass image to remain PseudoClass, use -colors.

2 IMAGE_CROPPING
To begin, press choose Crop of the Transform sub-menu from
the Command widget (see COMMAND WIDGET).  Alternatively, press [
in the Image window (see KEYBOARD ACCELERATORS).
 
A small window appears showing the location of the cursor in the image
window.  You are now in crop mode.  In crop mode, the Command
widget has these options:
 
    Help
    Dismiss
 
To define a cropping region, press button 1 and drag.  The cropping
region is defined by a highlighted rectangle that expands or contracts
as it follows the pointer.  Once you are satisfied with the cropping
region, release the button.  You are now in rectify mode.
In rectify mode, the Command widget has these options:
 
    Crop
    Help
    Dismiss
 
You can make adjustments by moving the pointer to one of the cropping
rectangle corners, pressing a button, and dragging.
Finally, press Crop to commit your cropping region.  To exit without
cropping the image, press Dismiss.

2 IMAGE_CHOPPING
An image is chopped interactively.  There is no command line argument to
chop an image.  To begin, choose Chop of the Transform
sub-menu from the Command widget (see COMMAND WIDGET).  Alternatively,
press ] in the Image window (see KEYBOARD ACCELERATORS).
 
You are now in Chop mode.  To exit immediately, press Dismiss.
In Chop mode, the Command widget has these options:
 
    Direction
      horizontal
      vertical
    Help
    Dismiss
 
If the you choose the horizontal direction (this is the default),
the area of the image between the two horizontal endpoints of the chop
line is removed.  Otherwise, the area of the image between the two
vertical endpoints of the chop line is removed.
 
Select a location within the Image window to begin your chop, press and hold
any button.  Next, move the pointer to another location in the image.  As you
move a line will connect the initial location and the pointer.  When you
release the button, the area within the image to chop is determined by
which direction you choose from the Command widget.
 
To cancel the image chopping, move the pointer back to the starting
point of the line and release the button.

2 IMAGE_ROTATION
Press the / key to rotate the image 90 degrees or \ to
rotate -90 degrees (see KEYBOARD ACCELERATORS).  To interactively
choose the degree of rotation, choose Rotate... of the Pixel
Transform submenu from the Command Widget (see COMMAND
WIDGET).  Alternatively, press * in the Image window (see
KEYBOARD ACCELERATORS).
 
A small horizontal line is drawn next to the pointer.  You are now in
rotate mode.  To exit immediately, press Dismiss.
In rotate mode, the Command widget has these options:
 
    Pixel Color
      black
      blue
      cyan
      green
      gray
      red
      magenta
      yellow
      white
      Browser...
    Direction
      horizontal
      vertical
    Help
    Dismiss
 
Choose a background color from the Pixel Color sub-menu.
Additional background colors can be specified with the color browser.
You can change the menu colors by setting the X resources pen1
through pen9.  Refer to X RESOURCES for more details.
 
If you choose the color browser and press Grab, you can select
the background color by moving the pointer to the desired color on the
screen and press any button. The transparent color updates the image
matte channel and is useful for image compositing.
 
Choose a point in the Image window and press this button and hold.
Next, move the pointer to another location in the image.  As you move a
line connects the initial location and the pointer.  When you release
the button, the degree of image rotation is determined by the slope of
the line you just drew.  The slope is relative to the direction you
choose from the Direction sub-menu of the Command widget.
 
To cancel the image rotation, move the pointer back to the starting
point of the line and release the button.

2 IMAGE_ANNOTATION
An image is annotated interactively.  There is no command line argument
to annotate an image.  To begin, choose Annotate of the Image
Edit sub-menu from the Command widget (see COMMAND WIDGET).
Alternatively, press a in the Image window (see KEYBOARD
ACCELERATORS).
 
A small window appears showing the location of the cursor in the image
window.  You are now in annotate mode.  To exit immediately,
press Dismiss.  In annotate mode, the Command widget has these
options:
 
    Font Name
      fixed
      variable
      5x8
      6x10
      7x13bold
      8x13bold
      9x15bold
      10x20
      12x24
      Browser...
    Font Color
      black
      blue
      cyan
      green
      gray
      red
      magenta
      yellow
      white
      transparent
      Browser...
    Box Color
      black
      blue
      cyan
      green
      gray
      red
      magenta
      yellow
      white
      transparent
      Browser...
    Rotate Text
    Rotate Text
      45
      90
      135
      180
      225
      270
      315
      Dialog...
    Help
    Dismiss
 
Choose a font name from the Font Name sub-menu.
Additional font names can be specified with the font browser.
You can change the menu names by setting the X resources font1
through font9.  Refer to X RESOURCES for more details.
 
Choose a font color from the Font Color sub-menu.
Additional font colors can be specified with the color browser.
You can change the menu colors by setting the X resources pen1
through pen9.  Refer to X RESOURCES for more details.
 
If you select the color browser and press Grab, you can choose
the font color by moving the pointer to the desired color on the screen
and press any button.
 
If you choose to rotate the text, choose Rotate Text from the
menu and select an angle.  Typically you will only want to
rotate one line of text at a time.  Depending on the angle you
choose, subsequent lines may end up overwriting each other.
 
Choosing a font and its color is optional.  The default font is
fixed and the default color is black.  However, you must
choose a location to begin entering text and press a button.  An
underscore character will appear at the location of the pointer.  The
cursor changes to a pencil to indicate you are in text mode.  To
exit immediately, press Dismiss.
 
In text mode, any key presses will display the character at
the location of the underscore and advance the underscore cursor.
Enter your text and once completed press Dismiss to finish your image
annotation.  To correct errors press BACK SPACE.  To delete an
entire line of text, press DELETE.  Any text that exceeds the
boundaries of the Image window is automatically continued onto the next
line.
 
The actual color you request for the font is saved in the image.
However, the color that appears in your Image window may be different.
For example, on a monochrome screen the text will appear black or white even
if you choose the color red as the font color.  However, the image saved to
a file with -write is written with red lettering.  To assure
the correct color text in the final image, any PseudoClass image
is promoted to DirectClass (see miff(5)).  To
force a PseudoClass image to remain PseudoClass, use
-colors.

2 IMAGE_COMPOSITING
An image composite is created interactively.  There is no command line
argument to composite an image.  To begin, choose Composite of
the Image Edit from the Command widget (see COMMAND
WIDGET).  Alternatively, press x in the Image window (see
KEYBOARD ACCELERATORS).
 
First a popup window is displayed requesting you to enter an image name.
Press Composite, Grab or type a file name.  Press Cancel
if you choose not to create a composite image.  When you choose Grab,
move the pointer to the desired window and press any button.
 
A small window appears showing the location of the cursor in the image
window. You are now in composite mode.  To exit immediately,
press Dismiss.  In composite mode, the Command widget has these
options:
 
    Operators
      over
      in
      out
      atop
      xor
      plus
      minus
      add
      subtract
      difference
      replace
    Blend
    Help
    Dismiss
 
Choose a composite operation from the Operators sub-menu of the
Command widget.  How each operator behaves is described below.
Image window is the image currently displayed on your X server and
image is the image obtained with the File Browser widget.
 
 
   over
The result is the union of the two image shapes, with image
obscuring Image window in the region of overlap.
 
   in
The result is simply image cut by the shape of image
window.  None of the image data of Image window is in the
result.
 
   out
The resulting image is image with the shape of Image window
cut out.
 
   atop
The result is the same shape as image Image window, with
image obscuring Image window where the image shapes
overlap.  Note this differs from over because the portion of
image outside Image window's shape does not appear in the
result.
 
   xor
The result is the image data from both image and Image window
that is outside the overlap region.  The overlap region is blank.
 
   plus
The result is just the sum of the image data.  Output values are
cropped to 255 (no overflow).  This operation is independent
of the matte channels.
 
   minus
The result of image - Image window, with underflow cropped
to zero.  The matte channel is ignored (set to 255, full coverage).
 
   add
The result of image + Image window, with overflow wrapping
around (mod 256).
 
   subtract
The result of image - Image window, with underflow wrapping
around (mod 256).  The add and subtract operators can
be used to perform reversible transformations.
 
   difference
The result of abs(image - Image window).  This is useful
for comparing two very similar images.
 
   replace
The resulting image is Image window replaced with image.
Here the matte information is ignored.
 
The image compositor requires a matte, or alpha channel in the image
for some operations.  This extra channel usually defines a mask which
represents a sort of a cookie-cutter for the image.  This is the case
when matte is 255 (full coverage) for pixels inside the shape, zero
outside, and between zero and 255 on the boundary.  If image does
not have a matte channel, it is initialized with 0 for any pixel
matching in color to pixel location (0,0), otherwise 255.  See
MATTE EDITING for a method of defining a matte channel.
 
If you choose Blend, the composite operator becomes Over.
The image matte channel percent transparency is initialized to
factor.  The image window is initialized to (100-factor).
Where factor is the value you specify in the Dialog widget.
 
Note that matte information for Image window is not retained for
colormapped X server visuals (e.g. StaticColor,
StaticColor, GrayScale, PseudoColor).  Correct
compositing behavior may require a TrueColor or DirectColor
visual or a Standard Colormap.
 
Choosing a composite operator is optional.  The default operator is
replace.  However, you must choose a location to composite your image
and press a button.  Press and hold the button before releasing and an
outline of the image will appear to help you identify your location.
 
The actual colors of the composite image is saved.  However, the color
that appears in Image window may be different.  For example, on a
monochrome screen Image window will appear black or white even
though your composited image may have many colors.  If the image is
saved to a file it is written with the correct colors.  To assure the
correct colors are saved in the final image, any PseudoClass
image is promoted to DirectClass (see miff(5)).  To force a
PseudoClass image to remain PseudoClass, use -colors.

2 COLOR_EDITING
Changing the the color of a set of pixels is performed interactively.
There is no command line argument to edit a pixel.  To begin, choose
Color from the Image Edit submenu of the Command widget
(see COMMAND WIDGET).  Alternatively, press c in the image
window (see KEYBOARD ACCELERATORS).
 
A small window appears showing the location of the cursor in the image
window. You are now in color edit mode.  To exit immediately,
press Dismiss.  In color edit mode, the Command widget has these
options:
 
    Pixel Color
      black
      blue
      cyan
      green
      gray
      red
      magenta
      yellow
      white
      Browser...
    Method
      point
      replace
      floodfill
    Delta
      0
      1
      2
      4
      8
      16
      32
      Browser...
    Undo
    Help
    Dismiss
 
Choose a pixel color from the Pixel Color sub-menu.
Additional pixel colors can be specified with the color browser.
You can change the menu colors by setting the X resources pen1
through pen9.  Refer to X RESOURCES for more details.
 
Next, choose a color editing method from the Method sub-menu of
the Command widget.  The point method recolors any pixel selected
with the pointer unless the button is released.  The replace
method recolors any pixel that matches the color of the pixel you
select with a button press.  Floodfill recolors any pixel that
matches the color of the pixel you select with a button press and is a
neighbor.
 
Now press a button to select a pixel within the Image window to change its
color.  Additional pixels may be recolored as prescribed by the method you
choose.  You can recolor additional pixels by increasing the Delta
value.  The Delta value is first added then subtracted from the red, green,
and blue of the target color.  Any pixels within the range is also
recolored.
 
If the Magnify widget is mapped, it can be helpful in positioning
your pointer within the image (refer to button 2).
 
The actual color you request for the pixels is saved in the image.
However, the color that appears in your Image window may be different.
For example, on a monochrome screen the pixel will appear black or
white even if you choose the color red as the pixel color.  However, the
image saved to a file with -write is written with red pixels.  To
assure the correct color text in the final image, any PseudoClass
image is promoted to DirectClass (see miff(5)).  To force a
PseudoClass image to remain PseudoClass, use -colors.

2 MATTE_EDITING
Matte information within an image is useful for some operations such as
image compositing (See IMAGE COMPOSITING).  This extra channel
usually defines a mask which represents a sort of a cookie-cutter for
the image.  This is the case when matte is 255 (full coverage) for
pixels inside the shape, zero outside, and between zero and 255 on the
boundary.
 
Setting the matte information in an image is done interactively.  There
is no command line argument to edit a pixel.  To begin, and choose
Matte of the Image Edit sub-menu from the Command widget
(see COMMAND WIDGET).  Alternatively, press m in the image
window (see KEYBOARD ACCELERATORS).
 
A small window appears showing the location of the cursor in the image
window. You are now in matte edit mode.  To exit immediately,
press Dismiss.  In matte edit mode, the Command widget has these
options:
 
    Method
      point
      replace
      floodfill
    Delta
      0
      1
      2
      4
      8
      16
      32
      Browser...
    Matte
    Undo
    Help
    Dismiss
 
Choose a matte editing method from the Method sub-menu of the
Command widget.  The point method changes the matte value of the
any pixel selected with the pointer until the button is released.  The
replace method changes the matte value of any pixel that matches
the color of the pixel you select with a button press.  Floodfill
changes the matte value of any pixel that matches the color of the pixel
you select with a button press and is a neighbor.
 
Choose Matte Value and a dialog appears requesting a matte value.  Enter
a value between 0 and 255.  This value is assigned as the matte value of the
selected pixel or pixels.
 
Now, press any button to select a pixel within the Image window to change
its matte value.  You can change the matte value of additional pixels by
increasing the Delta value.  The Delta value is first added then subtracted
from the red, green, and blue of the target color.  Any pixels within the
range also have their matte value updated.
 
If the Magnify widget is mapped, it can be helpful
in positioning your pointer within the image (refer to button 2).
 
Matte information is only valid in a DirectClass image.
Therefore, any PseudoClass image is promoted to DirectClass
(see miff(5)).  Note that matte information for PseudoClass
is not retained for colormapped X server visuals (e.g.
StaticColor, StaticColor, GrayScale,
PseudoColor) unless you immediately save your image to a file
(refer to Write).  Correct matte editing behavior may require a
TrueColor or DirectColor visual or a Standard Colormap.

2 IMAGE_DRAWING
An image is drawn upon interactively.  There is no command
line argument to draw on an image.  To begin, choose Draw of
the Image Edit sub-menu from the Command widget (see COMMAND
WIDGET).  Alternatively, press d in the Image window (see
KEYBOARD ACCELERATORS).
 
The cursor changes to a crosshair to indicate you are in draw mode.
To exit immediately, press Dismiss.  In draw mode, the Command
widget has these options:
 
    Primitive
      line
      rectangle
      fill rectangle
      ellipse
      fill ellipse
      polygon
      fill polygon
    Color
      black
      blue
      cyan
      green
      gray
      red
      magenta
      yellow
      white
      transparent
      Browser...
    Width
      1
      2
      4
      6
      8
      Dialog...
    Undo
    Help
    Dismiss
 
Choose a drawing primitive from the Primitive sub-menu.
 
Next, choose a color from the Color sub-menu.
Additional colors can be specified with the color browser.
You can change the menu colors by setting the X resources pen1
through pen9.  Refer to X RESOURCES for more details.
 
If you choose the color browser and press Grab, you can select
the primitive color by moving the pointer to the desired color on the
screen and press any button.
 
Choose a line width from the Width sub-menu.
To choose a specific width select the Dialog widget.
 
Choose a point in the Image window and press a button and hold.
Next, move the pointer to another location in the image.  As you move, a
line connects the initial location and the pointer.  When you release
the button, the image is updated with the primitive you just drew.
For polygons, the image is updated when you press and release the button
without moving the pointer.
 
To cancel image drawing, move the pointer back to the starting
point of the line and release the button.

2 REGION_OF_INTEREST
To begin, press choose Region of Interest of the Transform
sub-menu from the Command widget (see COMMAND WIDGET).  Alternatively,
press R in the Image window (see KEYBOARD ACCELERATORS).
 
A small window appears showing the location of the cursor in the image
window.  You are now in region of interest mode.  In region of
interest mode, the Command widget has these options:
 
    Help
    Dismiss
 
To define a region of interest, press button 1 and drag.  The region
of interest is defined by a highlighted rectangle that expands or contracts
as it follows the pointer.  Once you are satisfied with the region of
interest, release the button.  You are now in apply mode.
In apply mode the Command widget has these options:
 
    File
      Image Info
    Edit
      Undo
    Transform
      Flip
      Flop
      Rotate Right
      Rotate Left
    Enhance
      Hue...
      Saturation...
      Brightness...
      Gamma...
      Spiff
      Dull
      Equalize
      Normalize
      Negate
      Grayscale
      Quantize...
    Effects
      Despeckle
      Peak Noise
      Sharpen...
      Blur...
      Edge Detect
      Emboss
      Oil Painting
      Raise...
      Segment...
    Help
    Dismiss
 
You can make adjustments to the region of interest by moving the pointer to
one of the rectangle corners, pressing a button, and dragging.
Finally, choose an image processing technique from the Command widget.  You
can choose more than one image processing technique to apply to an area.
Alternatively, you can move the region of interest before applying
another image processing technique.  To exit, press Dismiss.

2 IMAGE_PANNING
When an image exceeds the width or height of the X server screen,
display maps a small panning icon.  The rectangle within the
panning icon shows the area that is currently displayed in the
the Image window.  To pan about the image, press any button and drag the
pointer within the panning icon.  The pan rectangle moves with the pointer
and the Image window is updated to reflect the location of the
rectangle within the panning icon.  When you have selected the area
of the image you wish to view, release the button.

Use the arrow keys to pan the image one pixel up, down, left, or right within
the Image window.

The panning icon is withdrawn if the image becomes smaller than the
dimensions of the X server screen.

2 USER_PREFERENCES
Preferences affect the default behavior of display(1).  The preferences
are either true or false:
 
    display image centered on a backdrop
This backdrop covers the entire workstation screen and is useful for
hiding other X window activity while viewing the image.   The color of
the backdrop is specified as the background color.  Refer to X
RESOURCES for details.
 
    confirm on program exit
Ask for a confirmation before exiting the display(1) program.
 
    correct image for display gamma
If the image has a known gamma, the gamma is corrected to match that of the
X server (see the X resource displayGamma).
 
    apply Floyd/Steinberg error diffusion to image
The basic strategy of dithering is to trade intensity resolution for
spatial resolution by averaging the intensities of several neighboring
pixels.  Images which suffer from severe contouring when reducing colors
can be improved with this perference.
 
    use a shared colormap for colormapped X visuals
This option only applies when the default X server visual is
PseudoColor or GrayScale.  Refer to -visual for more
details.  By default, a shared colormap is allocated.  The image shares
colors with other X clients.  Some image colors could be approximated,
therefore your image may look very different than intended.  Choose
Private and the image colors appear exactly as they are
defined.  However, other clients may go technicolor when the image
colormap is installed.
 
    display images as an X server pixmap
Images are maintained as a XImage by default.  Set this resource to True
to utilize a server Pixmap instead.  This option is useful if your image
exceeds the dimensions of your server screen and you intend to pan the
image.  Panning is much faster with Pixmaps than with a XImage.
Pixmaps are considered a precious resource, use them with discretion.

2 ENVIRONMENT
 
   display
To get the default host, display number, and screen.

2 COPYRIGHT
Copyright 1995 E. I. du Pont de Nemours and Company
 
Permission to use, copy, modify, distribute, and sell this software and
its documentation for any purpose is hereby granted without fee,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the name of E. I. du Pont de Nemours
and Company not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.  E. I. du Pont de Nemours and Company makes no representations
about the suitability of this software for any purpose.  It is provided
"as is" without express or implied warranty.
 
E. I. du Pont de Nemours and Company disclaims all warranties with regard
to this software, including all implied warranties of merchantability
and fitness, in no event shall E. I. du Pont de Nemours and Company be
liable for any special, indirect or consequential damages or any
damages whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortuous action, arising
out of or in connection with the use or performance of this software.

2 ACKNOWLEDGEMENTS
The MIT X Consortium for making network transparent graphics a reality.
 
Peder Langlo, Hewlett Packard, Norway, made hundreds of suggestions and bug
reports.  Without Peder, ImageMagick would not be nearly as useful as
it is today.
 
Rod Bogart and John W. Peterson, University of Utah.  Image
compositing is loosely based on rlecomp of the Utah Raster
Toolkit.
 
Michael Halle, Spatial Imaging Group at MIT, for the initial
implementation of Alan Paeth's image rotation algorithm.
 
David Pensak, E. I. du Pont de Nemours and Company, for providing a
computing environment that made this program possible.
 
Paul Raveling, USC Information Sciences Institute. The spacial
subdivision color reduction algorithm is based on his Img software.

2 AUTHORS
John Cristy, E.I. du Pont de Nemours and Company Incorporated
