>K [ 1 Q  Enumerationsp


Enumerations

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>Contents
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>ClassType
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ClassType specifies the image storage class.5  QO
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ClassType
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Enumeration

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Description

UndefinedClassUnset value.
DirectClassImage is composed of pixels which represent literal color values.
PseudoClassImage is composed of pixels which specify an index in a color palette.

 
>ColorspaceType
H

The ColorspaceType enumeration is used to specify the colorspace thatFquantization (color reduction and mapping) is done under or to specifyPthe colorspace when encoding an output image. Colorspaces are ways of describingLcolors to fit the requirements of a particular application (e.g. Television,Joffset printing, color monitors).  Color reduction, by default, takesMplace in the RGBColorspace. Empirical evidence suggests that distancesOin color spaces such as YUVColorspace or YIQColorspace correspondKto perceptual color differences more closely han do distances in RGB space.HThese color spaces may give better results when color reducing an image.*Refer to quantize for more details.G

When encoding an output image, the colorspaces RGBColorspace,CMYKColorspace,/and GRAYColorspace may be specified. TheCMYKColorspace optionFis only applicable when writing TIFF, JPEG, and Adobe Photoshop bitmap (PSD) files.
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ColorspaceType
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Enumeration

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Description

UndefinedColorspaceUnset value.
RGBColorspaceRed-Green-Blue colorspace.
GRAYColorspace 
TransparentColorspaceThe Transparent color space behaves uniquely in that it preserves the-matte channel of the image if it exists.
OHTAColorspace 
XYZColorspace 
YCbCrColorspace 
YCCColorspace 
YIQColorspace 
YPbPrColorspace 
YUVColorspaceY-signal, U-signal, and V-signal colorspace. YUV is most widely used8to encode color for use in television transmission.
CMYKColorspaceCyan-Magenta-Yellow-Black colorspace. CYMK is a subtractive color systemGused by printers and photographers for the rendering of colors with ink.or emulsion, normally on a white surface.
sRGBColorspace 

 
>CompositeOperator
M

CompositeOperator is used to select the image composition algorithmJused to compose a composite image with an image. By default,Jeach of the composite image pixels are replaced by the corresponding imageMtile pixel. Specify CompositeOperator to select a different algorithm.
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CompositeOperator
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Enumeration

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Description

UndefinedCompositeOpUnset value.
OverCompositeOpThe result is the union of the the two image shapes with the composite?image obscuring image in the region of overlap.
InCompositeOpThe result is a simply composite image cut by the shape of image.FNone of the image data of image is included in the result.
OutCompositeOpThe resulting image is composite image with the shape of image cut out.
AtopCompositeOpThe result is the same shape as image image, with compositeJimage obscuring image there the image shapes overlap. Note thatLthis differs from OverCompositeOp because the portion of compositeMimage outside of image's shape does not appear in the result.
XorCompositeOpThe result is the image data from both composite image and imageJthat is outside the overlap region. The overlap region will be blank.
PlusCompositeOpThe result is just the sum of the  image data. Output values areHcropped to 255 (no overflow). This operation is independent of the mattechannels.
MinusCompositeOpThe result of composite image - image, with overflowNcropped to zero. The matte chanel is ignored (set to 255, full coverage).
AddCompositeOpThe result of composite image + image, with overflowwrapping around (mod 256).
SubtractCompositeOpThe result of composite image - image, with underflowHwrapping around (mod 256). The add and subtract operators can be used to'perform reverible transformations.
DifferenceCompositeOpThe result of abs(composite image - image). This is useful+for comparing two very similar images.
BumpmapCompositeOpThe result image shaded by composite image.
ReplaceCompositeOpThe resulting image is image replaced with composite image.+Here the matte information is ignored.
ReplaceRedCompositeOpThe resulting image is the red layer in image replaced withTthe red layer in composite image. The other layers are copied untouched.
ReplaceGreenCompositeOpThe resulting image is the green layer in image replaced withFthe green layer in composite image. The other layers are copieduntouched.
ReplaceBlueCompositeOpThe resulting image is the blue layer in image replaced withUthe blue layer in composite image. The other layers are copied untouched.
ReplaceMatteCompositeOpThe resulting image is the matte layer in image replaced withFthe matte layer in composite image. The other layers are copied untouched.G

The image compositor requires a matte, or alpha channel in the imageOfor some operations. This extra channel usually defines a mask which representsGa sort of a cookie-cutter for the image. This is the case when matte isJ255 (full coverage) for pixels inside the shape, zero outside, and betweenKzero and 255 on the boundary.  For certain operations, if imageNdoes not have a matte channel, it is initialized with 0 for any pixel matchingTin color to pixel location (0,0), otherwise 255 (to work properly borderWidthmust be 0).


 
>CompressionType
I

CompressionType is used to express the desired compression typeMwhen encoding an image. Be aware that most image types only support a sub-setHof the available compression types. If the compression type specified isNincompatable with the image, ImageMagick selects a compression type compatablewith the image type.
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CompressionType
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Enumeration

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Description

UndefinedCompressionUnset value.
NoCompressionNo compression
BZipCompressionBZip (Burrows-Wheeler block-sorting text compression algorithm9and Huffman coding)  as used by bzip2 utilities
FaxCompressionCCITT Group 3 FAX compression
Group4CompressionCCITT Group 4 FAX compression (used only for TIFF)
JPEGCompressionJPEG compression
LZWCompressionLempel-Ziv-Welch (LZW) compression (caution, patented by Unisys)
RunlengthEncodedCompressionRun-Length encoded (RLE) compression
ZipCompressionLempel-Ziv compression (LZ77) as used in PKZIP and GNU gzip.

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>FilterType
N

FilterType is used to adjust the filter algorithm used when resizingLimages. Different filters experience varying degrees of success with variousFimages and can take sigificantly different amounts of processing time.FImageMagick uses the LanczosFilter by default since this filterJhas been shown to provide the best results for most images in a reasonableKamount of time. Other filter types (e.g. TriangleFilter) may executeGmuch faster but may show artifacts when the image is re-sized or aroundIdiagonal lines. The only way to be sure is to test the filter with sampleimages.
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FilterType
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Enumeration

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Description

UndefinedFilterUnset value.
PointFilterPoint Filter
BoxFilterBox Filter
TriangleFilterTriangle Filter
HermiteFilterHermite Filter
HanningFilterHanning Filter
HammingFilterHamming Filter
BlackmanFilterBlackman Filter
GaussianFilterGaussian Filter
QuadraticFilterQuadratic Filter
CubicFilterCubic Filter
CatromFilterCatrom Filter
MitchellFilterMitchell Filter
LanczosFilterLanczos Filter
BesselFilterBessel Filter
SincFilterSinc Filter

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>GravityType
K

GravityType specifies positioning of an object (e.g. text, image)Gwithin a bounding region (e.g. an image). Gravity provides a convenientFway to locate objects irrespective of the size of the bounding region,Gin other words, you don't need to provide absolute coordinates in orderOto position an object. A common default for gravity is NorthWestGravity.
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GravityType
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Enumeration

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Description

ForgetGravityDon't use gravity.
NorthWestGravityPosition object at top-left of region.
NorthGravityPostiion object at top-center of region
NorthEastGravityPosition object at top-right of region
WestGravityPosition object at left-center of region
CenterGravityPosition object at center of region
EastGravityPosition object at right-center of region
SouthWestGravityPosition object at left-bottom of region
SouthGravityPosition object at bottom-center of region
SouthEastGravityPosition object at bottom-right of region

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>ImageType
C

ImageType indicates the type classification of the image.
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ImageType
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Enumeration

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Description

UndefinedTypeUnset value.
BilevelTypeMonochrome image
GrayscaleTypeGrayscale image
PaletteTypeIndexed color (palette) image
PaletteMatteTypeIndexed color (palette) image with opacity
TrueColorTypeTruecolor image
TrueColorMatteTypeTruecolor image with opacity
ColorSeparationTypeCyan/Yellow/Magenta/Black (CYMK) image

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>InterlaceType
J

InterlaceType specifies the ordering of the red, green, and blueIpixel information in the image. Interlacing is usually used to make imageIinformation available to the user faster by taking advantage of the spaceFvs time tradeoff. For example, interlacing allows images on the Web toKbe recognizable sooner and satellite images to accumulate/render with image resolution increasing over time.L

Use LineInterlace or PlaneInterlace to create an interlacedGIF or progressive JPEG image.
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InterlaceType
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Enumeration

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Description

UndefinedInterlaceUnset value.
NoInterlaceDon't interlace image (RGBRGBRGBRGBRGBRGB...)
LineInterlaceUse scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...)
PlaneInterlaceUse plane interlacing (RRRRRR...GGGGGG...BBBBBB...)
PartitionInterlaceSimilar to plane interlaing except that the different planes are saved=to individual files (e.g. image.R, image.G, and image.B)

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>LayerType
H

LayerType is used as an argument when doing color separations.UseILayerType when extracting a layer from an image. MatteLayer:is useful for extracting the opacity values from an image.
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LayerType
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Enumeration

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Description

UndefinedLayerUnset value.
RedLayerSelect red layer
GreenLayerSelect green layer
BlueLayerSelect blue layer
MatteLayerSelect matte (opacity values) layer

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>NoiseType
F

NoiseType is used as an argument to select the type of noiseto be added to the image.
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NoiseType
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Enumeration

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Description

UniformNoiseUniform noise
GaussianNoiseGaussian noise
MultiplicativeGaussianNoiseMultiplicative Gaussian noise
ImpulseNoiseImpulse noise
LaplacianNoiseLaplacian noise
PoissonNoisePoisson noise

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>PaintMethod
F

PaintMethod specifies how pixel colors are to be replaced inEthe image. It is used to select the pixel-filling algorithm employed.
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PaintMethod
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Enumeration

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Description

PointMethodReplace pixel color at point.
ReplaceMethodReplace color for all image pixels matching color at point.
FloodfillMethodReplace color for pixels surrounding point until encountering.pixel that fails to match color at point.
FillToBorderMethodReplace color for pixels surrounding point until encountering pixelsmatching border color.
ResetMethodReplace colors for all pixels in image with pen color.

 
>RenderingIntent
S

Rendering intent is a concept defined by ICCFSpec ICC.1:1998-09, "File Format for Color Profiles". ImageMagick usesRenderingIntent'in order to support ICC Color Profiles.P

From the specification: "Rendering intent specifies the style of reproductionKto be used during the evaluation of this profile in a sequence of profiles.FIt applies specifically to that profile in the sequence and not to theJentire sequence. Typically, the user or application will set the rendering1intent dynamically at runtime or embedding time."
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RenderingIntent
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Enumeration

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Description

UndefinedIntentUnset value.
SaturationIntentA rendering intent that specifies the saturation of the pixelsGin the image is preserved perhaps at the expense of accuracy in hue andlightness.
PerceptualIntentA rendering intent that specifies the full gamut of the image is compressedHor expanded to fill the gamut of the destination device. Gray balance is@preserved but colorimetric accuracy might not be preserved.
AbsoluteIntentAbsolute colorimetric
RelativeIntentRelative colorimetric

 
>ResolutionType
X

By default, ImageMagick defines resolutions in pixels per inch. ResolutionType provides a means to adjust this.
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ResolutionType
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Enumeration

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Description

UndefinedResolutionUnset value.
PixelsPerInchResolutionDensity specifications are specified in units of pixels per inch (english units).
PixelsPerCentimeterResolutionDensity specifications are specified in units of pixels per centimeter(metric units).



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