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Add 4:1:1 subsampling support in the TurboJPEG Java API

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DRC
2013-08-18 11:04:21 +00:00
parent 2296d513c1
commit 45b2cca4c0
6 changed files with 76 additions and 17 deletions
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17
java/org/libjpegturbo/turbojpeg/TJ.java
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@@ -37,7 +37,7 @@ public final class TJ {
/**
* The number of chrominance subsampling options
*/
public static final int NUMSAMP = 5;
public static final int NUMSAMP = 6;
/**
* 4:4:4 chrominance subsampling (no chrominance subsampling). The JPEG
* or YUV image will contain one chrominance component for every pixel in the
@@ -64,6 +64,17 @@ public final class TJ {
* Note that 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
*/
public static final int SAMP_440 = 4;
/**
* 4:1:1 chrominance subsampling. The JPEG or YUV image will contain one
* chrominance component for every 4x1 block of pixels in the source image.
* JPEG images compressed with 4:1:1 subsampling will be almost exactly the
* same size as those compressed with 4:2:0 subsampling, and in the
* aggregate, both subsampling methods produce approximately the same
* perceptual quality. However, 4:1:1 is better able to reproduce sharp
* horizontal features. Note that 4:1:1 subsampling is not fully accelerated
* in libjpeg-turbo.
*/
public static final int SAMP_411 = 5;
/**
@@ -82,7 +93,7 @@ public final class TJ {
}
private static final int[] mcuWidth = {
8, 16, 16, 8, 8
8, 16, 16, 8, 8, 32
};
@@ -103,7 +114,7 @@ public final class TJ {
}
private static final int[] mcuHeight = {
8, 8, 16, 8, 16
8, 8, 16, 8, 16, 8
};