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.
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.
RGBColorspace
Red-Green-Blue colorspace.
GRAYColorspace
Grayscale colorspace
TransparentColorspace
The Transparent color space behaves uniquely in that it
preserves the matte channel of the image if it exists.
OHTAColorspace
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.
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.
sRGBColorspace
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 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
ZipCompression
Lempel-Ziv compression (LZ77) as used in PKZIP and GNU gzip.
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
OpacityQuantum
Opacity (Alpha) Quantum
CMY(K) Image Quantum
Enumeration
Description
CyanQuantum
Cyan pixel Quantum
MagentaQuantum
Magenta pixel Quantum
YellowQuantum
Yellow pixel Quantum
BlackQuantum
Black pixel Quantum
Grayscale Image
Quantums
Enumeration
Description
GrayQuantum
Gray pixel
GrayOpacityQuantum
Pixel opacity
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)
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.
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