Enumerations

> Contents

> ChannelType

ChannelType is used as an argument when doing color separations. Use ChannelType when extracting a layer from an image. MatteChannel is useful for extracting the opacity values from an image. Note that an image may be represented in RGB, RGBA, CMYK, or CMYKA, pixel formats and a channel may only be extracted if it is valid for the current pixel format.

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

ClassType specifies the image storage class.

ClassType

Enumeration

Description

UndefinedClass

Unset value.

DirectClass

Image is composed of pixels which represent literal color values.

PseudoClass

Image is composed of pixels which specify an index in a color palette.


> ColorspaceType

The ColorspaceType enumeration is used to specify the colorspace that quantization (color reduction and mapping) is done under or to specify the colorspace when encoding an output image. Colorspaces are ways of describing colors to fit the requirements of a particular application (e.g. Television, offset printing, color monitors). Color reduction, by default, takes place in the RGBColorspace. Empirical evidence suggests that distances in color spaces such as YUVColorspace or YIQColorspace correspond to perceptual color differences more closely han do distances in RGB space. These color spaces may give better results when color reducing an image. Refer to quantize for more details.

When encoding an output image, the colorspaces RGBColorspace, CMYKColorspace, and GRAYColorspace may be specified. The CMYKColorspace option is only applicable when writing TIFF, JPEG, and Adobe Photoshop bitmap (PSD) files.

ColorspaceType

Enumeration

Description

UndefinedColorspace

Unset value.

CMYKColorspace

Cyan-Magenta-Yellow-Black colorspace. CYMK is a subtractive color system used by printers and photographers for the rendering of 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 it preserves 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 widely used to encode color for use in television transmission.


> CompositeOperator

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

CompositeOperator

Enumeration

Description

UndefinedCompositeOp

Unset value.

OverCompositeOp

The result is the union of the two image shapes with the composite image obscuring image in the region of overlap.

InCompositeOp

The result is a simply composite image cut by the shape of image. None of the image data of image is included in the result.

OutCompositeOp

The resulting image is composite image with the shape of image cut out.

AtopCompositeOp

The result is the same shape as image image, with composite image obscuring image there the image shapes overlap. Note that this differs from OverCompositeOp because the portion of composite image outside of image's shape does not appear in the result.

XorCompositeOp

The result is the image data from both composite image and image that is outside the overlap region. The overlap region will be blank.

PlusCompositeOp

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.

MinusCompositeOp

The result of composite image - image, with overflow cropped to zero. The matte chanel is ignored (set to 255, full coverage).

AddCompositeOp

The result of composite image + image, with overflow wrapping around (mod 256).

SubtractCompositeOp

The result of composite image - image, with underflow wrapping around (mod 256). The add and subtract operators can be used to perform reverible transformations.

DifferenceCompositeOp

The result of abs(composite image - image). This is useful for comparing two very similar images.

MultiplyCompositeOp

BumpmapCompositeOp

The result image shaded by composite image.

CopyCompositeOp

The resulting image is image replaced with composite image. Here the matte information is ignored.

CopyRedCompositeOp

The resulting image is the red layer in image replaced with the red layer in composite image. The other layers are copied untouched.

CopyGreenCompositeOp

The resulting image is the green layer in image replaced with the green layer in composite image. The other layers are copied untouched.

CopyBlueCompositeOp

The resulting image is the blue layer in image replaced with the blue layer in composite image. The other layers are copied untouched.

CopyOpacityCompositeOp

The resulting image is the matte layer in image replaced with the matte layer in composite image. The other layers are copied untouched.

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. For certain operations, 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 (to work properly borderWidth must be 0).

ClearCompositeOp

DissolveCompositeOp

DisplaceCompositeOp

ModulateCompositeOp

ThresholdCompositeOp


>CompressionType

CompressionType is used to express the desired compression type when encoding an image. Be aware that most image types only support a sub-set of the available compression types. If the compression type specified is incompatable with the image, ImageMagick selects a compression type compatable with the image type.

CompressionType

Enumeration

Description

UndefinedCompression

Unset value.

NoCompression

No compression

BZipCompression

BZip (Burrows-Wheeler block-sorting text compression algorithm and 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 by Unisys)

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/).


> DecorationType

The DecorationType enumerations are used to specify line decorations of rendered text.

DecorationType

Enumeration

Description

NoDecoration

No decoration

UnderlineDecoration

Underlined text

OverlineDecoration

Overlined text

LineThroughDecoration

Strike-through text


>EndianType

The EndianType enumerations are used 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

FillRule specifies the algorithm which is to be used to determine what parts of the canvas are included inside the shape. See the documentation on SVG's fill-rule property for usage details.

FillRule

UndefinedRule

Fill rule not specified

EvenOddRule

See SVG fill-rule evenodd rule.

NonZeroRule

See SVG fill-rule nonzero rule.


>FilterTypes

FilterTypes is used to adjust the filter algorithm used when resizing images. Different filters experience varying degrees of success with various images and can take sipngicantly different amounts of processing time. ImageMagick uses the LanczosFilter by default since this filter has been shown to provide the best results for most images in a reasonable amount of time. Other filter types (e.g. TriangleFilter) may execute much faster but may show artifacts when the image is re-sized or around diagonal lines. The only way to be sure is to test the 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

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

GravityType

Enumeration

Description

ForgetGravity

Don't use gravity.

NorthWestGravity

Position object at top-left of region.

NorthGravity

Postiion 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

ImageType indicates the type classification 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

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

Use LineInterlace or PlaneInterlace to create an interlaced GIF or progressive JPEG image.

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 interlaing except that the different planes are saved to individual files (e.g. image.R, image.G, and image.B)


>ChannelType

ChannelType is used as an argument when doing color separations. Use ChannelType when extracting a layer from an image. MatteLayer is useful for extracting 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


>LineCap

The LineCap enumerations specify shape 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 stroke width).

SquareCap

Square ending, extended by 1/2 the stroke width at end.


>LineJoin

The LineJoin enumerations specify the shape to be used at the corners of paths or basic shapes when 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

NoiseType is used as an argument to 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


>OrientationType

OrientationType specifies the orientation of the image. Useful for when the image is produced via a different ordinate system, the camera was turned on its 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

PaintMethod specifies how pixel colors are to be replaced in the image. It is used to select the pixel-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 encountering pixel that fails to match color at point.

FillToBorderMethod

Replace color for pixels surrounding point until encountering pixels matching border color.

ResetMethod

Replace colors for all pixels in image with pen color.


>QuantumTypes

QuantumTypes is used to indicate the source or destination format of entire pixels, or components of pixels ("Quantums") while they are being read, or written to, a pixel cache. The validity of these format specifications depends on whether the Image pixels are in RGB format, RGBA format, or CMYK format. The pixel Quantum size is determined by the Image depth (eight or sixteen bits).

RGB(A) Image Quantums

Enumeration

Description

IndexQuantum

PseudoColor colormap indices (valid only for image with colormap)

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 Image Quantums

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)


>RenderingIntent

Rendering intent is a concept defined by ICC Spec ICC.1:1998-09, "File Format for Color Profiles". ImageMagick uses RenderingIntent in order to support ICC Color Profiles.

From the specification: "Rendering intent specifies the style of reproduction to be used during the evaluation of this profile in a sequence of profiles. It applies specifically to that profile in the sequence and not to the entire sequence. Typically, the user or application will set the rendering intent dynamically at runtime or embedding time."

RenderingIntent

Enumeration

Description

UndefinedIntent

Unset value.

SaturationIntent

A rendering intent that specifies the saturation of the pixels in the image is preserved perhaps at the expense of accuracy in hue and lightness.

PerceptualIntent

A rendering intent that specifies the full gamut of the image is compressed or expanded to fill the gamut of the destination device. Gray balance is preserved but colorimetric accuracy might not be preserved.

AbsoluteIntent

Absolute colorimetric

RelativeIntent

Relative colorimetric


>ResolutionType

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

ResolutionType

Enumeration

Description

UndefinedResolution

Unset value.

PixelsPerInchResolution

Density specifications are specified in units of pixels per inch (english units).

PixelsPerCentimeterResolution

Density specifications are specified in units of pixels per centimeter (metric units).


>StorageType

The StorageType enumerations are used to specify the storage format of pixels in the source or destination pixel array.

StorageType

Enumeration

Description

CharPixel

Character type

ShortPixel

Short type

IntegerPixel

Integer type

FloatPixel

Float type

DoublePixel

Double type


>StretchType

The StretchType enumerations are used to specify the relative width of a font to the regular width for the font family. If the width is not important, the AnyStretch enumeration 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


>StyleType

The StyleType enumerations are used to specify the style (e.g. Italic) of a font. If the style is not important, the AnyStyle enumeration may be specified for a wildcard match.

StyleType

Enumeration

Description

AnyStyle

Wildcard match for font style

NormalStyle

Normal font style

ItalicStyle

Italic font style

ObliqueStyle

Oblique font style


>VirtualPixelMethod

The VirtualPixelMethod enumerations are used 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