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Add CMYK support to the TurboJPEG Java API & clean up a few things in the C API

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git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@1020 632fc199-4ca6-4c93-a231-07263d6284db
This commit is contained in:
DRC
2013-08-23 04:45:43 +00:00
parent cd7c3e6672
commit 38cb1ec2a7
18 changed files with 497 additions and 73 deletions
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80
java/org/libjpegturbo/turbojpeg/TJ.java
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@@ -121,7 +121,7 @@ public final class TJ {
/**
* The number of pixel formats
*/
public static final int NUMPF = 11;
public static final int NUMPF = 12;
/**
* RGB pixel format. The red, green, and blue components in the image are
* stored in 3-byte pixels in the order R, G, B from lowest to highest byte
@@ -191,6 +191,21 @@ public final class TJ {
* interpreted as an opaque alpha channel.
*/
public static final int PF_ARGB = 10;
/**
* CMYK pixel format. Unlike RGB, which is a display colorspace,
* CMYK (Cyan/Magenta/Yellow/Key) is a print colorspace in which the
* value of each color component corresponds to the amount of cyan, magenta,
* yellow, or black ink that is applied to a white background. In order to
* convert between CMYK and RGB, it is necessary to use a color management
* system (CMS.) A CMS will attempt to map colors within the printer's gamut
* to perceptually similar colors in the display's gamut and vice versa, but
* the mapping is typically not 1:1 or reversible, nor can it be defined with
* a simple formula. Thus, such a conversion is out of scope for a codec
* library. However, the TurboJPEG API allows for compressing CMYK pixels
* into a YCCK JPEG image (see {@link #CS_YCCK}) and decompressing YCCK JPEG
* images into CMYK pixels.
*/
public static final int PF_CMYK = 11;
/**
@@ -207,7 +222,7 @@ public final class TJ {
}
private static final int[] pixelSize = {
3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4
3, 3, 4, 4, 4, 4, 1, 4, 4, 4, 4, 4
};
@@ -229,7 +244,7 @@ public final class TJ {
}
private static final int[] redOffset = {
0, 2, 0, 2, 3, 1, 0, 0, 2, 3, 1
0, 2, 0, 2, 3, 1, 0, 0, 2, 3, 1, -1
};
@@ -251,7 +266,7 @@ public final class TJ {
}
private static final int[] greenOffset = {
1, 1, 1, 1, 2, 2, 0, 1, 1, 2, 2
1, 1, 1, 1, 2, 2, 0, 1, 1, 2, 2, -1
};
@@ -273,10 +288,65 @@ public final class TJ {
}
private static final int[] blueOffset = {
2, 0, 2, 0, 1, 3, 0, 2, 0, 1, 3
2, 0, 2, 0, 1, 3, 0, 2, 0, 1, 3, -1
};
/**
* The number of JPEG colorspaces
*/
public static final int NUMCS = 5;
/**
* RGB colorspace. When compressing the JPEG image, the R, G, and B
* components in the source image are reordered into image planes, but no
* colorspace conversion or subsampling is performed. RGB JPEG images can be
* decompressed to any of the extended RGB pixel formats or grayscale, but
* they cannot be decompressed to YUV images.
*/
public static final int CS_RGB = 0;
/**
* YCbCr colorspace. YCbCr is not an absolute colorspace but rather a
* mathematical transformation of RGB designed solely for storage and
* transmission. YCbCr images must be converted to RGB before they can
* actually be displayed. In the YCbCr colorspace, the Y (luminance)
* component represents the black & white portion of the original image, and
* the Cb and Cr (chrominance) components represent the color portion of the
* original image. Originally, the analog equivalent of this transformation
* allowed the same signal to drive both black & white and color televisions,
* but JPEG images use YCbCr primarily because it allows the color data to be
* optionally subsampled for the purposes of reducing bandwidth or disk
* space. YCbCr is the most common JPEG colorspace, and YCbCr JPEG images
* can be compressed from and decompressed to any of the extended RGB pixel
* formats or grayscale, or they can be decompressed to YUV planar images.
*/
public static final int CS_YCbCr = 1;
/**
* Grayscale colorspace. The JPEG image retains only the luminance data (Y
* component), and any color data from the source image is discarded.
* Grayscale JPEG images can be compressed from and decompressed to any of
* the extended RGB pixel formats or grayscale, or they can be decompressed
* to YUV planar images.
*/
public static final int CS_GRAY = 2;
/**
* CMYK colorspace. When compressing the JPEG image, the C, M, Y, and K
* components in the source image are reordered into image planes, but no
* colorspace conversion or subsampling is performed. CMYK JPEG images can
* only be decompressed to CMYK pixels.
*/
public static final int CS_CMYK = 3;
/**
* YCCK colorspace. YCCK (AKA "YCbCrK") is not an absolute colorspace but
* rather a mathematical transformation of CMYK designed solely for storage
* and transmission. It is to CMYK as YCbCr is to RGB. CMYK pixels can be
* reversibly transformed into YCCK, and as with YCbCr, the chrominance
* components in the YCCK pixels can be subsampled without incurring major
* perceptual loss. YCCK JPEG images can only be compressed from and
* decompressed to CMYK pixels.
*/
public static final int CS_YCCK = 4;
/**
* The uncompressed source/destination image is stored in bottom-up (Windows,
* OpenGL) order, not top-down (X11) order.