Enumerations
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ChannelType is used as anargument when doing color separations. UseChannelTypewhenextracting a layer from an image.MatteChannel is useful forextracting the opacity values from an image. Note that an image maybe represented in RGB, RGBA, CMYK, or CMYKA, pixel formats and achannel may only be extracted if it is valid for the current pixelformat.
ChannelType
Enumeration | Description |
UndefinedChannel | Unset value. |
RedChannel | Extract red channel (RGB images only) |
CyanChannel | Extract cyan channel (CMYK images only) |
GreenChannel | Extract green channel (RGB images only) |
MagentaChannel | Extract magenta channel (CMYK images only) |
BlueChannel | Extract blue channel (RGB images only) |
YellowChannel | Extract yellow channel (CMYK images only) |
OpacityChannel | Extract matte (opacity values) channel (CMYKA images only) |
BlackChannel | Extract black channel (CMYK images only) |
MatteChannel | Extract matte (opacity values) channel (RGB images only) |
ClassType specifies the imagestorage class.
ClassType
Enumeration | Description |
UndefinedClass | Unset value. |
DirectClass | Image is composed of pixels which represent literal colorvalues. |
PseudoClass | Image is composed of pixels which specify an index in a colorpalette. |
The ColorspaceType enumeration is used to specify the colorspacethat quantization (color reduction and mapping) is done under or tospecify the colorspace when encoding an output image. Colorspaces areways of describing colors to fit the requirements of a particularapplication (e.g. Television, offset printing, color monitors). Color reduction, by default, takes place in theRGBColorspace.Empirical evidence suggests that distances in color spaces such asYUVColorspace orYIQColorspace correspond to perceptualcolor differences more closely han do distances in RGB space. Thesecolor spaces may give better results when color reducing an image.Refer toquantize for more details.
When encoding an output image, thecolorspacesRGBColorspace,CMYKColorspace, andGRAYColorspace may be specified. TheCMYKColorspaceoption is only applicable when writing TIFF, JPEG, and AdobePhotoshop bitmap (PSD) files.
ColorspaceType
Enumeration | Description |
UndefinedColorspace | Unset value. |
CMYKColorspace | Cyan-Magenta-Yellow-Black colorspace. CYMK is a subtractivecolor system used by printers and photographers for the renderingof colors with ink or emulsion, normally on a white surface. |
GRAYColorspace | Grayscale colorspace |
HCLColorspace | |
LabColorspace | |
LCHabColorspace | |
LuvColorspace | |
OHTAColorspace | |
RGBColorspace | Red-Green-Blue colorspace. |
sRGBColorspace | |
scRGBColorspace | |
TransparentColorspace | The Transparent color space behaves uniquely in that itpreserves the matte channel of the image if it exists. |
XYZColorspace | |
YCbCrColorspace | |
YCCColorspace | |
YIQColorspace | |
YPbPrColorspace | |
YUVColorspace | Y-signal, U-signal, and V-signal colorspace. YUV is most widelyused to encode color for use in television transmission. |
CompositeOperator is used toselect the image composition algorithm used to compose acompositeimage with animage. By default, each of the compositeimage pixels are replaced by the corresponding image tile pixel.SpecifyCompositeOperator to select a different algorithm.
CompositeOperator
Enumeration | Description |
UndefinedCompositeOp | Unset value. |
OverCompositeOp | The result is the union of the two image shapes with thecomposite image obscuringimage in the region ofoverlap. |
InCompositeOp | The result is a simplycomposite imagecut by the shapeof image. None of the image data ofimage is included inthe result. |
OutCompositeOp | The resulting image iscomposite image with the shape ofimage cut out. |
AtopCompositeOp | The result is the same shape as imageimage, withcomposite image obscuringimage there the imageshapes overlap. Note that this differs fromOverCompositeOpbecause the portion ofcomposite image outside ofimage'sshape does not appear in the result. |
XorCompositeOp | The result is the image data from both composite imageandimage that is outside the overlap region. The overlapregion will be blank. |
PlusCompositeOp | The result is just the sum of the image data. Outputvalues are cropped to 255 (no overflow). This operation isindependent of the matte channels. |
MinusCompositeOp | The result ofcomposite image-image, withoverflow cropped to zero. The matte channel is ignored (set to 255,full coverage). |
AddCompositeOp | The result ofcomposite image +image, withoverflow wrapping around (mod 256). |
SubtractCompositeOp | The result ofcomposite image-image, withunderflow wrapping around (mod 256). The add and subtractoperators can be used to perform reversible transformations. |
DifferenceCompositeOp | The result of abs(composite image-image). Thisis useful for comparing two very similar images. |
MultiplyCompositeOp | |
BumpmapCompositeOp | The resultimage shaded bycomposite image. |
CopyCompositeOp | The resultingimage is image replaced with compositeimage. Here the matte information is ignored. |
CopyRedCompositeOp | The resulting image is the red layer inimage replacedwith the red layer incomposite image. The other layers arecopied untouched. |
CopyGreenCompositeOp | The resulting image is the green layer inimage replacedwith the green layer incomposite image. The other layersare copied untouched. |
CopyBlueCompositeOp | The resulting image is the blue layer inimage replacedwith the blue layer incomposite image. The other layersare copied untouched. |
CopyOpacityCompositeOp | The resulting image is the matte layer inimage replacedwith the matte layer incomposite image. The other layersare copied untouched. The image compositor requires a matte, or alpha channel in theimage for some operations. This extra channel usually defines amask which represents a sort of a cookie-cutter for the image.This is the case when matte is 255 (full coverage) for pixelsinside the shape, zero outside, and between zero and 255 on theboundary. For certain operations, ifimage does nothave a matte channel, it is initialized with 0 for any pixelmatching in color to pixel location (0,0), otherwise 255 (to workproperlyborderWidth must be 0). |
ClearCompositeOp | |
DissolveCompositeOp | |
DisplaceCompositeOp | |
ModulateCompositeOp | |
ThresholdCompositeOp |
CompressionType is used toexpress the desired compression type when encoding an image. Be awarethat most image types only support a sub-set of the availablecompression types. If the compression type specified is incompatiblewith the image, ImageMagick selects a compression type compatiblewith the image type.
CompressionType
Enumeration | Description |
UndefinedCompression | Unset value. |
NoCompression | No compression |
BZipCompression | BZip (Burrows-Wheeler block-sorting text compression algorithmand Huffman coding) as used by bzip2 utilities |
FaxCompression | CCITT Group 3 FAX compression |
Group4Compression | CCITT Group 4 FAX compression (used only for TIFF) |
JPEGCompression | JPEG compression |
LZWCompression | Lempel-Ziv-Welch (LZW) compression (caution, patented byUnisys) |
RunlengthEncodedCompression | Run-Length encoded (RLE) compression |
WebPCompression | WebP compression. |
ZipCompression | Lempel-Ziv compression (LZ77) as used in PKZIP and GNU gzip. |
ZstdCompression | Zstd compression (https://facebook.github.io/zstd/). |
TheDecorationTypeenumerationsare used to specify line decorations of rendered text.
DecorationType
Enumeration | Description |
NoDecoration | No decoration |
UnderlineDecoration | Underlined text |
OverlineDecoration | Overlined text |
LineThroughDecoration | Strike-through text |
TheEndianTypeenumerations areused to specify the endian option for formats which support it (e.g.TIFF).
EndianType
Enumeration | Description |
UndefinedEndian | Not defined (default) |
LSBEndian | Little endian (like Intel X86 and DEC Alpha) |
MSBEndian | Big endian (like Motorola 68K, Mac PowerPC, & SPARC) |
FillRule specifies the algorithmwhich is to be used to determine what parts of the canvas areincluded inside the shape. See the documentation on SVG'sfill-rule property for usage details.
FillRule
UndefinedRule | Fill rule not specified |
EvenOddRule | See SVG fill-ruleevenodd rule. |
NonZeroRule | See SVG fill-rulenonzero rule. |
FilterTypes is used to adjustthe filter algorithm used when resizing images. Different filtersexperience varying degrees of success with various images and cantake significantly different amounts of processing time.ImageMagick uses theLanczosFilter by default since thisfilter has been shown to provide the best results for most images ina reasonable amount of time. Other filter types (e.g.TriangleFilter)may execute much faster but may show artifacts when the image isre-sized or around diagonal lines. The only way to be sure is to testthe filter with sample images.
FilterTypes
Enumeration | Description |
UndefinedFilter | Unset value. |
PointFilter | Point Filter |
BoxFilter | Box Filter |
TriangleFilter | Triangle Filter |
HermiteFilter | Hermite Filter |
HanningFilter | Hanning Filter |
HammingFilter | Hamming Filter |
BlackmanFilter | Blackman Filter |
GaussianFilter | Gaussian Filter |
QuadraticFilter | Quadratic Filter |
CubicFilter | Cubic Filter |
CatromFilter | Catrom Filter |
MitchellFilter | Mitchell Filter |
LanczosFilter | Lanczos Filter |
BesselFilter | Bessel Filter |
SincFilter | Sinc Filter |
GravityType specifiespositioning of an object (e.g. text, image) within a bounding region(e.g. an image). Gravity provides a convenient way to locate objectsirrespective of the size of the bounding region, in other words, youdon't need to provide absolute coordinates in order to position anobject. A common default for gravity isNorthWestGravity.
GravityType
Enumeration | Description |
ForgetGravity | Don't use gravity. |
NorthWestGravity | Position object at top-left of region. |
NorthGravity | Position object at top-center of region |
NorthEastGravity | Position object at top-right of region |
WestGravity | Position object at left-center of region |
CenterGravity | Position object at center of region |
EastGravity | Position object at right-center of region |
SouthWestGravity | Position object at left-bottom of region |
SouthGravity | Position object at bottom-center of region |
SouthEastGravity | Position object at bottom-right of region |
ImageType indicates the typeclassification of the image.
ImageType
Enumeration | Description |
UndefinedType | Unset value. |
BilevelType | Monochrome image |
GrayscaleType | Grayscale image |
GrayscaleMatteType | Grayscale image with opacity |
PaletteType | Indexed color (palette) image |
PaletteMatteType | Indexed color (palette) image with opacity |
TrueColorType | Truecolor image |
TrueColorMatteType | Truecolor image with opacity |
ColorSeparationType | Cyan/Yellow/Magenta/Black (CYMK) image |
InterlaceType specifies the ordering of the red, green, andblue pixel information in the image. Interlacing is usually used tomake image information available to the user faster by takingadvantage of the space vs time tradeoff. For example, interlacingallows images on the Web to be recognizable sooner and satelliteimages to accumulate/render with image resolution increasing overtime.
UseLineInterlace orPlaneInterlace to create an interlaced GIF or progressive JPEGimage.
InterlaceType
Enumeration | Description |
UndefinedInterlace | Unset value. |
NoInterlace | Don't interlace image (RGBRGBRGBRGBRGBRGB...) |
LineInterlace | Use scanline interlacing (RRR...GGG...BBB...RRR...GGG...BBB...) |
PlaneInterlace | Use plane interlacing (RRRRRR...GGGGGG...BBBBBB...) |
PartitionInterlace | Similar to plane interlacing except that the different planesare saved to individual files (e.g. image.R, image.G, and image.B) |
ChannelType is used as anargument when doing color separations. UseChannelType whenextracting a layer from an image.MatteLayer is useful forextracting the opacity values from an image.
ChannelType
Enumeration | Description |
UndefinedLayer | Unset value. |
RedLayer | Select red layer |
GreenLayer | Select green layer |
BlueLayer | Select blue layer |
MatteLayer | Select matte (opacity values) layer |
TheLineCap enumerations specifyshape to be used at the end of open subpaths when they are stroked.See SVG's 'stroke-linecap'for examples.
LineCap
Enumeration | Description |
UndefinedCap | Unset value. |
ButtCap | Square ending. |
RoundCap | Rounded ending (half-circle end with radius of 1/2 strokewidth). |
SquareCap | Square ending, extended by 1/2 the stroke width at end. |
TheLineJoin enumerationsspecify the shape to be used at the corners of paths or basic shapeswhen they are stroked. See SVG's 'stroke-linejoin'for examples.
ChannelType
Enumeration | Description |
UndefinedJoin | Unset value. |
MiterJoin | Sharp-edged join |
RoundJoin | Rounded-edged join |
BevelJoin | Beveled-edged join |
NoiseType is used as an argumentto select the type of noise to be added to the image.
NoiseType
Enumeration | Description |
UniformNoise | Uniform noise |
GaussianNoise | Gaussian noise |
MultiplicativeGaussianNoise | Multiplicative Gaussian noise |
ImpulseNoise | Impulse noise |
LaplacianNoise | Laplacian noise |
PoissonNoise | Poisson noise |
OrientationTypespecifies the orientation of the image. Useful for when the image isproduced via a different ordinate system, the camera was turned onits side, or the page was scanned sideways.
OrientationType
Enumeration | Scanline Direction | Frame Direction |
UndefinedOrientation | Unknown | Unknown |
TopLeftOrientation | Left to right | Top to bottom |
TopRightOrientation | Right to left | Top to bottom |
BottomRightOrientation | Right to left | Bottom to top |
BottomLeftOrientation | Left to right | Bottom to top |
LeftTopOrientation | Top to bottom | Left to right |
RightTopOrientation | Top to bottom | Right to left |
RightBottomOrientation | Bottom to top | Right to left |
LeftBottomOrientation | Bottom to top | Left to right |
PaintMethod specifies how pixelcolors are to be replaced in the image. It is used to select thepixel-filling algorithm employed.
PaintMethod
Enumeration | Description |
PointMethod | Replace pixel color at point. |
ReplaceMethod | Replace color for all image pixels matching color at point. |
FloodfillMethod | Replace color for pixels surrounding point until encounteringpixel that fails to match color at point. |
FillToBorderMethod | Replace color for pixels surrounding point until encounteringpixels matching border color. |
ResetMethod | Replace colors forall pixels in image with pen color. |
QuantumTypes is used to indicatethe source or destination format of entire pixels, or components ofpixels ("Quantums") while they are being read, or writtento, a pixel cache. The validity of these format specificationsdepends on whether the Image pixels are in RGB format, RGBA format,or CMYK format. The pixel Quantum size is determined by the Imagedepth (eight or sixteen bits).
RGB(A) Image Quantums
Enumeration | Description |
IndexQuantum | PseudoColor colormap indices (valid only for image withcolormap) |
RedQuantum | Red pixel Quantum |
GreenQuantum | Green pixel Quantum |
BlueQuantum | Blue pixel Quantum |
AlphaQuantum | Alpha Quantum |
CMY(K)(A) Image Quantum
Enumeration | Description |
CyanQuantum | Cyan pixel Quantum |
MagentaQuantum | Magenta pixel Quantum |
YellowQuantum | Yellow pixel Quantum |
BlackQuantum | Black pixel Quantum |
AlphaQuantum | Alpha Quantum |
Grayscale ImageQuantums
Enumeration | Description |
GrayQuantum | Gray pixel |
GrayOpacityQuantum | Pixel opacity |
AlphaQuantum | Alpha Quantum |
Entire Pixels(Expressed in Byte Order)
Enumeration | Description |
RGBQuantum | RGB pixel (24 or 48 bits) |
RGBAQuantum | RGBA pixel (32 or 64 bits) |
CMYKQuantum | CMYK pixel (32 or 64 bits) |
CMYKAQuantum | CMYKA pixel (40 or 80 bits) |
Rendering intent is a concept defined byICCSpec ICC.1:1998-09, "File Format for Color Profiles".ImageMagick usesRenderingIntent in order to support ICCColor Profiles.
From the specification: "Renderingintent specifies the style of reproduction to be used during theevaluation of this profile in a sequence of profiles. It appliesspecifically to that profile in the sequence and not to the entiresequence. Typically, the user or application will set the renderingintent dynamically at runtime or embedding time."
RenderingIntent
Enumeration | Description |
UndefinedIntent | Unset value. |
SaturationIntent | A rendering intent that specifies the saturation of the pixelsin the image is preserved perhaps at the expense of accuracy inhue and lightness. |
PerceptualIntent | A rendering intent that specifies the full gamut of the imageis compressed or expanded to fill the gamut of the destinationdevice. Gray balance is preserved but colorimetric accuracy mightnot be preserved. |
AbsoluteIntent | Absolute colorimetric |
RelativeIntent | Relative colorimetric |
By default, ImageMagick definesresolutions in pixels per inch.ResolutionType provides ameans to adjust this.
ResolutionType
Enumeration | Description |
UndefinedResolution | Unset value. |
PixelsPerInchResolution | Density specifications are specified in units of pixels perinch (english units). |
PixelsPerCentimeterResolution | Density specifications are specified in units of pixels percentimeter (metric units). |
TheStorageType enumerations areused to specify the storage format of pixels in the source ordestination pixel array.
StorageType
Enumeration | Description |
CharPixel | Character type |
ShortPixel | Short type |
IntegerPixel | Integer type |
FloatPixel | Float type |
DoublePixel | Double type |
TheStretchType enumerations areused to specify the relative width of a font to the regular width forthe font family. If the width is not important, theAnyStretchenumeration may be specified for a wildcard match.
StretchType
Enumeration | Description |
AnyStretch | Wildcard match for font stretch |
NormalStretch | Normal width font |
UltraCondensedStretch | Ultra-condensed (narrowest) font |
ExtraCondensedStretch | Extra-condensed font |
CondensedStretch | Condensed font |
SemiCondensedStretch | Semi-Condensed font |
SemiExpandedStretch | Semi-Expanded font |
ExpandedStretch | Expanded font |
ExtraExpandedStretch | Extra-Expanded font |
UltraExpandedStretch | Ultra-expanded (widest) font |
TheStyleType enumerations areused to specify the style (e.g. Italic) of a font. If the style isnot important, theAnyStyle enumeration may be specified for awildcard match.
StyleType
Enumeration | Description |
AnyStyle | Wildcard match for font style |
NormalStyle | Normal font style |
ItalicStyle | Italic font style |
ObliqueStyle | Oblique font style |
TheVirtualPixelMethodenumerations areused to specify the virtual pixel method.
VirtualPixelMethod
Enumeration | Description |
UndefinedVirtualPixelMethod | Not defined |
BackgroundVirtualPixelMethod | the area surrounding the image is the background color |
BlackVirtualPixelMethod | the area surrounding the image is black |
CheckerTileVirtualPixelMethod | alternate squares with image and background color |
DitherVirtualPixelMethod | non-random 32x32 dithered pattern |
EdgeVirtualPixelMethod | extend the edge pixel toward infinity |
GrayVirtualPixelMethod | the area surrounding the image is gray |
HorizontalTileVirtualPixelMethod | horizontally tile the image, background color above/below |
HorizontalTileEdgeVirtualPixelMethod | horizontally tile the image and replicate the side edge pixels |
MirrorVirtualPixelMethod | mirror tile the image |
RandomVirtualPixelMethod | choose a random pixel from the image |
TileVirtualPixelMethod | tile the image (default) |
TransparentVirtualPixelMethod | the area surrounding the image is transparent blackness |
VerticalTileVirtualPixelMethod | vertically tile the image, sides are background color |
VerticalTileEdgeVirtualPixelMethod | vertically tile the image and replicate the side edge pixels |
WhiteVirtualPixelMethod | the area surrounding the image is white |