Enum pdfium_render::color_space::PdfColorSpace
source · [−]pub enum PdfColorSpace {
Unknown,
DeviceGray,
DeviceRGB,
DeviceCMYK,
CalibratedCIEGray,
CalibratedCIERGB,
CalibratedCIELab,
CalibratedICCProfile,
Separation,
DeviceN,
Indexed,
Pattern,
}Expand description
The color space of any displayable object on a PdfPage.
Colors can be described in any of a variety of color systems called color spaces. Some color spaces are related to device color representation (e.g. grayscale, RGB, CMYK); others are related to human visual perception.
Color spaces can be classified into color space families. Spaces within a family share the same general characteristics. Families fall into three broad categories:
- Device color spaces directly specify colors or shades of gray that the output device is to produce. The precise displayed color is device-specific and is not calibrated. Color space families in this category include PdfColorSpace::DeviceGray, PdfColorSpace::DeviceRGB, and PdfColorSpace::DeviceCMYK.
- Calibrated color spaces are based on international standards for specifying human-visible colors created by the Commission Internationale de l’Éclairage (International Commission on Illumination) and the International Color Consortium. The precise displayed color is device-independent; it does not rely on the characteristics of any particular output device. Color space families in this category include PdfColorSpace::CalibratedCIEGray, PdfColorSpace::CalibratedCIERGB, PdfColorSpace::CalibratedCIELab, and PdfColorSpace::CalibratedICCProfile.
- Special color spaces add features or properties to another color space, such as patterns, color mapping, separations, and high-fidelity and/or multi-tone color. Color space families in this category include PdfColorSpace::Pattern, PdfColorSpace::Indexed, PdfColorSpace::Separation, and PdfColorSpace::DeviceN.
Non-RGB color spaces typically define a transform that enables color values in the color space to be converted to an RGB approximation for on-screen display.
For more information on color spaces and their utilisation in PDF files, see Section 4.5 of the PDF Reference Manual version 1.7, starting on page 235.
Variants
Unknown
An unknown or unset color space. Color spaces were added to the PDF file format gradually from versions 1.1 to versions 1.3.
DeviceGray
Black, white, and intermediate shades of gray are special cases of full color.
A grayscale value is represented by a single number in the range 0.0..=1.0, where
0.0 corresponds to black, 1.0 to white, and intermediate values to different gray levels.
This is a non-calibrated color space; the exact color produced for a particular set of component values may vary slightly from device to device.
DeviceRGB
Colors in this color space are specified according to the additive Red-Green-Blue color
model used by light-emitting displays and projectors. Color values are defined by three
components representing the intensities of the additive primary colorants red, green,
and blue. Each component is specified by a number in the range 0.0..=1.0, where
0.0 corresponds to a complete absence of the component and 1.0 corresponds to maximum
intensity of the component. If all three components have equal intensity, the perceived
result theoretically is a pure gray on the scale from black to white. If the intensities
are not all equal, the result is some color other than a pure gray.
This is a non-calibrated color space; the exact color produced for a particular set of component values may vary slightly from device to device.
DeviceCMYK
Colors in this color space are specified according to the subtractive Cyan-Magenta-Yellow-Black
model typical of printers and other paper-based output devices. In theory, each of the three
standard process colorants used in printing (cyan, magenta, and yellow) absorbs one of the
additive primary colors (red, green, and blue, respectively). Black, a fourth standard process
colorant, absorbs all of the additive primaries in equal amounts. Color values are defined
by four components representing the concentrations of these process colorants. Each component
is specified by a number in the range 0.0..=1.0, where 0.0 denotes the complete absence of
a process colorant (that is, absorbs none of the corresponding additive primary) and 1.0
denotes maximum concentration (absorbs as much as possible of the additive primary). Note
that the sense of these numbers is opposite to that of RGB color components.
This is a non-calibrated color space; the exact color produced for a particular set of component values may vary slightly from device to device.
CalibratedCIEGray
Colors in this color space are specified by a single component, arbitrarily named A, that represents the gray component of a calibrated gray color space.
This is a calibrated color space, based on the tristimulus components of the CIE 1931 XYZ color space. The three components of the color space are defined in terms of human color vision and are independent of any particular output device.
CalibratedCIERGB
Colors in this color space are specified by three components, arbitrarily named A, B, and C,
representing calibrated red, green, and blue color values. These three color components must
be in the range 0.0..=1.0.
This is a calibrated color space, based on the tristimulus components of the CIE 1931 XYZ color space. The three components of the color space are defined in terms of human color vision and are independent of any particular output device.
CalibratedCIELab
Colors in this color space are specified by three components, named L*, a*, and b*, of a CIE 1976 L*a*b color space. The range of the first (L*) component is always 0 to 100; the ranges of the second (a*) and third (b*) components are defined by the color space.
This is a calibrated color space; the three components of the color space are defined in terms of human color vision and are independent of any particular output device.
CalibratedICCProfile
Colors in this color space are based on a cross-platform color profile defined by the International Color Consortium (ICC).
This is a calibrated color space; colors are defined by international standards and are independent of any particular output device.
Separation
Some output devices, such as image-setters, produce a separate, monochromatic rendition of a page - a separation - for each colorant. When the separations are later combined - on a printing press, for example - with proper inks or other colorants added to them, the result is a full-color page.
This special color space provides a means for specifying the use of additional colorants, called a tint, or for isolating the control of individual color components of a device color space for a subtractive device.
DeviceN
Colors in this special color space can contain an arbitrary number of color components. This provides greater flexibility than is possible with standard device color spaces or with individual separation color spaces. DeviceN color spaces are used in applications such as high-fidelity color (such as the Pantone Hexachrome system), multi-tone color systems (such as duotone), and spot color systems (using subtractive colorants outside the standard Cyan-Magenta-Yellow-Black model).
Indexed
This special color space indicates an object or area should be painted according to color values stored in a lookup table rather than a color space.
Pattern
This special color space indicates an object or area should be painted using a pattern, rather than a single color.
Trait Implementations
sourceimpl Clone for PdfColorSpace
impl Clone for PdfColorSpace
sourcefn clone(&self) -> PdfColorSpace
fn clone(&self) -> PdfColorSpace
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
source. Read more