| Value | Meaning |
|---|---|
| UndefinedColorspace | No colorspace has been specified. |
| RGBColorspace | Linear RGB colorspace |
| GRAYColorspace | Full-range grayscale |
| TransparentColorspace | The Transparent color space behaves uniquely in that it preserves the matte channel of the image if it exists. |
| OHTAColorspace | Red-Green-Blue colorspace |
| LabColorspace | ditto |
| XYZColorspace | CIE XYZ |
| YCbCrColorspace | Kodak PhotoCD PhotoYCC |
| YCCColorspace | ditto |
| YIQColorspace | Y-signal, U-signal, and V-signal colorspace. YUV is most widely used to encode color for use in television transmission. |
| YPbPrColorspace | ditto |
| YUVColorspace | ditto |
| 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 | Kodak PhotoCD sRGB. |
| HSBColorspace | Hue, saturation, luminosity |
| HSLColorspace | ditto |
| HWBColorspace | Hue, whiteness, blackness |
| Rec601LumaColorspace | Luma (Y) according to ITU-R 601 |
| Rec601YCbCrColorspace | YCbCr according to ITU-R 601 |
| Rec709LumaColorspace | Luma (Y) according to ITU-R 709 |
| Rec709YCbCrColorspace | YCbCr according to ITU-R 709 |
| LogColorspace | Red-Green-Blue colorspace |
| CMYColorspace | 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. |
| LuvColorspace | CIE 1976 (L*, u*, v*) color space. |
| HCLColorspace | HCL is a color space that tries to combine the advantages of perceptual uniformity of Luv, and the simplicity of specification of HSV and HSL. |
| LCHColorspace | Alias for LCHuv. |
| LMSColorspace | LMS is a color space represented by the response of the three types of cones of the human eye, named after their responsivity (sensitivity) at long, medium and short wavelengths. |
| LCHabColorspace | CIE 1976 cylindrical version of Lab. |
| LCHuvColorspace | CIE 1976 cylindrical version of Luv |
| scRGBColorspace | scRGB is a wide color gamut RGB (Red Green Blue) color space created by Microsoft and HP that uses the same color primaries and white/black points as the sRGB color space but allows coordinates below zero and greater than one. |
| HSIColorspace | |
| HSVColorspace | |
| HCLpColorspace | |
| YDbDrColorspace | |
| xyYColorspace | In CIE xyY, Y is the luminance and x and y represents the chrominance values derived from the tristimulus values X, Y and Z in the CIE XYZ color space. |
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 than do distances in RGB space. These color spaces may give better results when color reducing an image.
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.