static int |
SAMP_GRAY
Grayscale.
@@ -978,6 +984,31 @@ extends java.lang.Object
- See Also:
- Constant Field Values
+
+
+
+
diff --git a/java/doc/org/libjpegturbo/turbojpeg/TJCompressor.html b/java/doc/org/libjpegturbo/turbojpeg/TJCompressor.html
index e8d73427..b86891d8 100644
--- a/java/doc/org/libjpegturbo/turbojpeg/TJCompressor.html
+++ b/java/doc/org/libjpegturbo/turbojpeg/TJCompressor.html
@@ -471,7 +471,14 @@ implements java.io.Closeable
public void setJPEGQuality(int quality)
Set the JPEG image quality level for subsequent compress operations.
- Parameters:
quality - the new JPEG image quality level (1 to 100, 1 = worst,
- 100 = best)
+ 100 = best.) When generating a lossless JPEG image (see
+ TJ.FLAG_LOSSLESS), quality is
+ psv * 10 + Pt, where psv is the predictor
+ selection value (1-7) and Pt is the point transform (0-7). A
+ point transform value of 0 is necessary in order to create a fully
+ lossless JPEG image. (A non-zero point transform value right-shifts the
+ input samples by the specified number of bits, which is effectively a form
+ of lossy color quantization.)
diff --git a/java/org/libjpegturbo/turbojpeg/TJ.java b/java/org/libjpegturbo/turbojpeg/TJ.java
index 92d28566..98e01f14 100644
--- a/java/org/libjpegturbo/turbojpeg/TJ.java
+++ b/java/org/libjpegturbo/turbojpeg/TJ.java
@@ -377,7 +377,7 @@ public final class TJ {
* The uncompressed source/destination image is stored in bottom-up (Windows,
* OpenGL) order, not top-down (X11) order.
*/
- public static final int FLAG_BOTTOMUP = 2;
+ public static final int FLAG_BOTTOMUP = (1 << 1);
/**
* When decompressing an image that was compressed using chrominance
@@ -386,7 +386,7 @@ public final class TJ {
* creates a smooth transition between neighboring chrominance components in
* order to reduce upsampling artifacts in the decompressed image.
*/
- public static final int FLAG_FASTUPSAMPLE = 256;
+ public static final int FLAG_FASTUPSAMPLE = (1 << 8);
/**
* Use the fastest DCT/IDCT algorithm available in the underlying codec. The
* default if this flag is not specified is implementation-specific. For
@@ -395,7 +395,7 @@ public final class TJ {
* only a very slight effect on accuracy, but it uses the accurate algorithm
* when decompressing, because this has been shown to have a larger effect.
*/
- public static final int FLAG_FASTDCT = 2048;
+ public static final int FLAG_FASTDCT = (1 << 11);
/**
* Use the most accurate DCT/IDCT algorithm available in the underlying
* codec. The default if this flag is not specified is
@@ -405,7 +405,7 @@ public final class TJ {
* but it uses the accurate algorithm when decompressing, because this has
* been shown to have a larger effect.
*/
- public static final int FLAG_ACCURATEDCT = 4096;
+ public static final int FLAG_ACCURATEDCT = (1 << 12);
/**
* Immediately discontinue the current compression/decompression/transform
* operation if the underlying codec throws a warning (non-fatal error). The
@@ -417,7 +417,7 @@ public final class TJ {
* with a void return type) will complete and leave the output image in a
* fully recoverable state after a non-fatal error occurs.
*/
- public static final int FLAG_STOPONWARNING = 8192;
+ public static final int FLAG_STOPONWARNING = (1 << 13);
/**
* Use progressive entropy coding in JPEG images generated by compression and
* transform operations. Progressive entropy coding will generally improve
@@ -425,7 +425,7 @@ public final class TJ {
* reduce compression and decompression performance considerably. Can be
* combined with {@link #FLAG_ARITHMETIC}.
*/
- public static final int FLAG_PROGRESSIVE = 16384;
+ public static final int FLAG_PROGRESSIVE = (1 << 14);
/**
* Limit the number of progressive JPEG scans that the decompression and
* transform operations will process. If a progressive JPEG image contains
@@ -435,7 +435,7 @@ public final class TJ {
* against an exploit of the progressive JPEG format described in
* this report.
*/
- public static final int FLAG_LIMITSCANS = 32768;
+ public static final int FLAG_LIMITSCANS = (1 << 15);
/**
* Use arithmetic entropy coding in JPEG images generated by compression and
* transform operations. Arithmetic entropy coding will generally improve
@@ -443,7 +443,25 @@ public final class TJ {
* reduce compression and decompression performance considerably. Can be
* combined with {@link #FLAG_PROGRESSIVE}.
*/
- public static final int FLAG_ARITHMETIC = 65536;
+ public static final int FLAG_ARITHMETIC = (1 << 16);
+ /**
+ * Generate a lossless JPEG image when compressing. In most cases,
+ * compressing and decompressing lossless JPEG images is considerably slower
+ * than compressing and decompressing lossy JPEG images. Also note that the
+ * following features are not available with lossless JPEG images:
+ *
+ * - Colorspace conversion
+ *
- Chrominance subsampling
+ *
- JPEG quality selection
+ *
- DCT/IDCT algorithm selection
+ *
- Progressive entropy coding
+ *
- Arithmetic entropy coding
+ *
- Compression from/decompression to YUV planar images
+ *
- Decompression scaling
+ *
- Lossless transformations
+ *
+ */
+ public static final int FLAG_LOSSLESS = (1 << 17);
/**
* The number of error codes
diff --git a/java/org/libjpegturbo/turbojpeg/TJCompressor.java b/java/org/libjpegturbo/turbojpeg/TJCompressor.java
index 250f42d0..d7d2976f 100644
--- a/java/org/libjpegturbo/turbojpeg/TJCompressor.java
+++ b/java/org/libjpegturbo/turbojpeg/TJCompressor.java
@@ -1,5 +1,6 @@
/*
- * Copyright (C)2011-2015, 2018, 2020 D. R. Commander. All Rights Reserved.
+ * Copyright (C)2011-2015, 2018, 2020, 2022 D. R. Commander.
+ * All Rights Reserved.
* Copyright (C)2015 Viktor Szathmáry. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -283,7 +284,14 @@ public class TJCompressor implements Closeable {
* Set the JPEG image quality level for subsequent compress operations.
*
* @param quality the new JPEG image quality level (1 to 100, 1 = worst,
- * 100 = best)
+ * 100 = best.) When generating a lossless JPEG image (see
+ * {@link TJ#FLAG_LOSSLESS}), quality is
+ * psv * 10 + Pt, where psv is the predictor
+ * selection value (1-7) and Pt is the point transform (0-7). A
+ * point transform value of 0 is necessary in order to create a fully
+ * lossless JPEG image. (A non-zero point transform value right-shifts the
+ * input samples by the specified number of bits, which is effectively a form
+ * of lossy color quantization.)
*/
public void setJPEGQuality(int quality) {
if (quality < 1 || quality > 100)
diff --git a/java/org/libjpegturbo/turbojpeg/TJTransform.java b/java/org/libjpegturbo/turbojpeg/TJTransform.java
index c655bf19..214768cf 100644
--- a/java/org/libjpegturbo/turbojpeg/TJTransform.java
+++ b/java/org/libjpegturbo/turbojpeg/TJTransform.java
@@ -103,21 +103,21 @@ public class TJTransform extends Rectangle {
* partial MCU blocks that cannot be transformed will be left in place, which
* will create odd-looking strips on the right or bottom edge of the image.
*/
- public static final int OPT_PERFECT = 1;
+ public static final int OPT_PERFECT = (1 << 0);
/**
* This option will discard any partial MCU blocks that cannot be
* transformed.
*/
- public static final int OPT_TRIM = 2;
+ public static final int OPT_TRIM = (1 << 1);
/**
* This option will enable lossless cropping.
*/
- public static final int OPT_CROP = 4;
+ public static final int OPT_CROP = (1 << 2);
/**
* This option will discard the color data in the input image and produce
* a grayscale output image.
*/
- public static final int OPT_GRAY = 8;
+ public static final int OPT_GRAY = (1 << 3);
/**
* This option will prevent {@link TJTransformer#transform
* TJTransformer.transform()} from outputting a JPEG image for this
@@ -125,7 +125,7 @@ public class TJTransform extends Rectangle {
* filter to capture the transformed DCT coefficients without transcoding
* them.
*/
- public static final int OPT_NOOUTPUT = 16;
+ public static final int OPT_NOOUTPUT = (1 << 4);
/**
* This option will enable progressive entropy coding in the output image
* generated by this particular transform. Progressive entropy coding will
@@ -133,13 +133,13 @@ public class TJTransform extends Rectangle {
* default), but it will reduce compression and decompression performance
* considerably. Can be combined with {@link #OPT_ARITHMETIC}.
*/
- public static final int OPT_PROGRESSIVE = 32;
+ public static final int OPT_PROGRESSIVE = (1 << 5);
/**
* This option will prevent {@link TJTransformer#transform
* TJTransformer.transform()} from copying any extra markers (including EXIF
* and ICC profile data) from the source image to the output image.
*/
- public static final int OPT_COPYNONE = 64;
+ public static final int OPT_COPYNONE = (1 << 6);
/**
* This option will enable arithmetic entropy coding in the output image
* generated by this particular transform. Arithmetic entropy coding will
@@ -147,7 +147,7 @@ public class TJTransform extends Rectangle {
* default), but it will reduce compression and decompression performance
* considerably. Can be combined with {@link #OPT_PROGRESSIVE}.
*/
- public static final int OPT_ARITHMETIC = 128;
+ public static final int OPT_ARITHMETIC = (1 << 7);
/**
diff --git a/tjbench.c b/tjbench.c
index b6848c43..b26c8f2f 100644
--- a/tjbench.c
+++ b/tjbench.c
@@ -775,6 +775,11 @@ static void usage(char *progName)
printf("-arithmetic = Use arithmetic entropy coding in JPEG images generated by\n");
printf(" compression and transform operations. (Can be combined with\n");
printf(" -progressive.)\n");
+ printf("-lossless = Generate lossless JPEG images (implies -subsamp 444). When\n");
+ printf(" generating lossless JPEG images, Quality is psv * 10 + Pt, where psv is\n");
+ printf(" the predictor selection value (1-7) and Pt is the point transform (0-7).\n");
+ printf(" A point transform value of 0 is necessary in order to create a fully\n");
+ printf(" lossless JPEG image.\n");
printf("-subsamp = When testing JPEG compression, this option specifies the level\n");
printf(" of chrominance subsampling to use ( = 444, 422, 440, 420, 411, or\n");
printf(" GRAY). The default is to test Grayscale, 4:2:0, 4:2:2, and 4:4:4 in\n");
@@ -874,6 +879,10 @@ int main(int argc, char *argv[])
} else if (!strcasecmp(argv[i], "-arithmetic")) {
printf("Using arithmetic entropy coding\n\n");
flags |= TJFLAG_ARITHMETIC;
+ } else if (!strcasecmp(argv[i], "-lossless")) {
+ printf("Using lossless JPEG\n\n");
+ flags |= TJFLAG_LOSSLESS;
+ subsamp = TJSAMP_444;
} else if (!strcasecmp(argv[i], "-rgb"))
pf = TJPF_RGB;
else if (!strcasecmp(argv[i], "-rgbx"))
diff --git a/tjunittest.c b/tjunittest.c
index b3f03113..f010be25 100644
--- a/tjunittest.c
+++ b/tjunittest.c
@@ -58,6 +58,7 @@ static void usage(char *progName)
printf("-yuv = test YUV encoding/decoding support\n");
printf("-noyuvpad = do not pad each line of each Y, U, and V plane to the nearest\n");
printf(" 4-byte boundary\n");
+ printf("-lossless = test lossless JPEG compression/decompression\n");
printf("-alloc = test automatic buffer allocation\n");
printf("-bmp = tjLoadImage()/tjSaveImage() unit test\n\n");
exit(1);
@@ -95,7 +96,7 @@ const int _4byteFormats[] = {
const int _onlyGray[] = { TJPF_GRAY };
const int _onlyRGB[] = { TJPF_RGB };
-int doYUV = 0, alloc = 0, pad = 4;
+int doYUV = 0, lossless = 0, alloc = 0, pad = 4, psv = 1;
int exitStatus = 0;
#define BAILOUT() { exitStatus = -1; goto bailout; }
@@ -157,7 +158,7 @@ static void initBuf(unsigned char *buf, int w, int h, int pf, int flags)
#define CHECKVAL(v, cv) { \
- if (v < cv - 1 || v > cv + 1) { \
+ if (v < cv - (1 - lossless) || v > cv + (1 - lossless)) { \
printf("\nComp. %s at %d,%d should be %d, not %d\n", #v, row, col, cv, \
v); \
retval = 0; exitStatus = -1; goto bailout; \
@@ -165,14 +166,14 @@ static void initBuf(unsigned char *buf, int w, int h, int pf, int flags)
}
#define CHECKVAL0(v) { \
- if (v > 1) { \
+ if (v > (1 - lossless)) { \
printf("\nComp. %s at %d,%d should be 0, not %d\n", #v, row, col, v); \
retval = 0; exitStatus = -1; goto bailout; \
} \
}
#define CHECKVAL255(v) { \
- if (v < 254) { \
+ if (v < 255 - (1 - lossless)) { \
printf("\nComp. %s at %d,%d should be 255, not %d\n", #v, row, col, v); \
retval = 0; exitStatus = -1; goto bailout; \
} \
@@ -433,6 +434,8 @@ static void _decompTest(tjhandle handle, unsigned char *jpegBuf,
TRY_TJ(tjDecompressHeader2(handle, jpegBuf, jpegSize, &_hdrw, &_hdrh,
&_hdrsubsamp));
+ if (lossless && subsamp != TJSAMP_444 && subsamp != TJSAMP_GRAY)
+ subsamp = TJSAMP_444;
if (_hdrw != w || _hdrh != h || _hdrsubsamp != subsamp)
THROW("Incorrect JPEG header");
@@ -493,8 +496,15 @@ static void decompTest(tjhandle handle, unsigned char *jpegBuf,
char *basename, int subsamp, int flags)
{
int i, n = 0;
- tjscalingfactor *sf = tjGetScalingFactors(&n);
+ tjscalingfactor *sf = NULL, sf1 = { 1, 1 };
+ if (lossless) {
+ _decompTest(handle, jpegBuf, jpegSize, w, h, pf, basename, subsamp, flags,
+ sf1);
+ return;
+ }
+
+ sf = tjGetScalingFactors(&n);
if (!sf || !n) THROW_TJ();
for (i = 0; i < n; i++) {
@@ -518,7 +528,7 @@ static void doTest(int w, int h, const int *formats, int nformats, int subsamp,
tjhandle chandle = NULL, dhandle = NULL;
unsigned char *dstBuf = NULL;
unsigned long size = 0;
- int pfi, pf, i;
+ int pfi, pf, i, quality = 100;
if (!alloc)
size = tjBufSize(w, h, subsamp);
@@ -534,12 +544,16 @@ static void doTest(int w, int h, const int *formats, int nformats, int subsamp,
for (i = 0; i < 2; i++) {
int flags = 0;
+ if (lossless) {
+ flags |= TJFLAG_LOSSLESS;
+ quality = (((psv++ - 1) % 7) + 1) * 10;
+ }
if (subsamp == TJSAMP_422 || subsamp == TJSAMP_420 ||
subsamp == TJSAMP_440 || subsamp == TJSAMP_411)
flags |= TJFLAG_FASTUPSAMPLE;
if (i == 1) flags |= TJFLAG_BOTTOMUP;
pf = formats[pfi];
- compTest(chandle, &dstBuf, &size, w, h, pf, basename, subsamp, 100,
+ compTest(chandle, &dstBuf, &size, w, h, pf, basename, subsamp, quality,
flags);
decompTest(dhandle, dstBuf, size, w, h, pf, basename, subsamp, flags);
if (pf >= TJPF_RGBX && pf <= TJPF_XRGB) {
@@ -601,11 +615,19 @@ static void bufSizeTest(void)
unsigned char *srcBuf = NULL, *dstBuf = NULL;
tjhandle handle = NULL;
unsigned long dstSize = 0;
+ int flags = 0, quality = 100, numSamp = TJ_NUMSAMP;
+
+ if (!alloc) flags |= TJFLAG_NOREALLOC;
+ if (lossless) {
+ flags |= TJFLAG_LOSSLESS;
+ quality = (((psv++ - 1) % 7) + 1) * 10;
+ numSamp = 1;
+ }
if ((handle = tjInitCompress()) == NULL) THROW_TJ();
printf("Buffer size regression test\n");
- for (subsamp = 0; subsamp < TJ_NUMSAMP; subsamp++) {
+ for (subsamp = 0; subsamp < numSamp; subsamp++) {
for (w = 1; w < 48; w++) {
int maxh = (w == 1) ? 2048 : 48;
@@ -630,8 +652,7 @@ static void bufSizeTest(void)
subsamp, 0));
} else {
TRY_TJ(tjCompress2(handle, srcBuf, w, 0, h, TJPF_BGRX, &dstBuf,
- &dstSize, subsamp, 100,
- alloc ? 0 : TJFLAG_NOREALLOC));
+ &dstSize, subsamp, quality, flags));
}
free(srcBuf); srcBuf = NULL;
if (!alloc || doYUV) {
@@ -657,8 +678,7 @@ static void bufSizeTest(void)
subsamp, 0));
} else {
TRY_TJ(tjCompress2(handle, srcBuf, h, 0, w, TJPF_BGRX, &dstBuf,
- &dstSize, subsamp, 100,
- alloc ? 0 : TJFLAG_NOREALLOC));
+ &dstSize, subsamp, quality, flags));
}
free(srcBuf); srcBuf = NULL;
if (!alloc || doYUV) {
@@ -899,27 +919,34 @@ int main(int argc, char *argv[])
for (i = 1; i < argc; i++) {
if (!strcasecmp(argv[i], "-yuv")) doYUV = 1;
else if (!strcasecmp(argv[i], "-noyuvpad")) pad = 1;
+ else if (!strcasecmp(argv[i], "-lossless")) lossless = 1;
else if (!strcasecmp(argv[i], "-alloc")) alloc = 1;
else if (!strcasecmp(argv[i], "-bmp")) return bmpTest();
else usage(argv[0]);
}
}
+ if (lossless && doYUV)
+ THROW("Lossless JPEG and YUV encoding/decoding are incompatible.");
if (alloc) printf("Testing automatic buffer allocation\n");
if (doYUV) num4bf = 4;
overflowTest();
doTest(35, 39, _3byteFormats, 2, TJSAMP_444, "test");
doTest(39, 41, _4byteFormats, num4bf, TJSAMP_444, "test");
doTest(41, 35, _3byteFormats, 2, TJSAMP_422, "test");
- doTest(35, 39, _4byteFormats, num4bf, TJSAMP_422, "test");
- doTest(39, 41, _3byteFormats, 2, TJSAMP_420, "test");
- doTest(41, 35, _4byteFormats, num4bf, TJSAMP_420, "test");
- doTest(35, 39, _3byteFormats, 2, TJSAMP_440, "test");
- doTest(39, 41, _4byteFormats, num4bf, TJSAMP_440, "test");
- doTest(41, 35, _3byteFormats, 2, TJSAMP_411, "test");
- doTest(35, 39, _4byteFormats, num4bf, TJSAMP_411, "test");
+ if (!lossless) {
+ doTest(35, 39, _4byteFormats, num4bf, TJSAMP_422, "test");
+ doTest(39, 41, _3byteFormats, 2, TJSAMP_420, "test");
+ doTest(41, 35, _4byteFormats, num4bf, TJSAMP_420, "test");
+ doTest(35, 39, _3byteFormats, 2, TJSAMP_440, "test");
+ doTest(39, 41, _4byteFormats, num4bf, TJSAMP_440, "test");
+ doTest(41, 35, _3byteFormats, 2, TJSAMP_411, "test");
+ doTest(35, 39, _4byteFormats, num4bf, TJSAMP_411, "test");
+ }
doTest(39, 41, _onlyGray, 1, TJSAMP_GRAY, "test");
- doTest(41, 35, _3byteFormats, 2, TJSAMP_GRAY, "test");
- doTest(35, 39, _4byteFormats, 4, TJSAMP_GRAY, "test");
+ if (!lossless) {
+ doTest(41, 35, _3byteFormats, 2, TJSAMP_GRAY, "test");
+ doTest(35, 39, _4byteFormats, 4, TJSAMP_GRAY, "test");
+ }
bufSizeTest();
if (doYUV) {
printf("\n--------------------\n\n");
@@ -932,5 +959,6 @@ int main(int argc, char *argv[])
doTest(48, 48, _onlyGray, 1, TJSAMP_GRAY, "test_yuv0");
}
+ bailout:
return exitStatus;
}
diff --git a/turbojpeg.c b/turbojpeg.c
index dc9d6d8c..cb8abe1a 100644
--- a/turbojpeg.c
+++ b/turbojpeg.c
@@ -272,13 +272,14 @@ static int getPixelFormat(int pixelSize, int flags)
return -1;
}
-static void setCompDefaults(struct jpeg_compress_struct *cinfo,
- int pixelFormat, int subsamp, int jpegQual,
- int flags)
+static int setCompDefaults(tjhandle handle, int pixelFormat, int subsamp,
+ int jpegQual, int flags)
{
#ifndef NO_GETENV
char env[7] = { 0 };
#endif
+ int retval = 0;
+ GET_CINSTANCE(handle);
cinfo->in_color_space = pf2cs[pixelFormat];
cinfo->input_components = tjPixelSize[pixelFormat];
@@ -307,7 +308,13 @@ static void setCompDefaults(struct jpeg_compress_struct *cinfo,
}
#endif
- if (jpegQual >= 0) {
+ if (flags & TJFLAG_LOSSLESS) {
+ int psv = jpegQual / 10, pt = jpegQual % 10;
+
+ if (psv < 1 || psv > 7 || pt < 0 || pt > 7)
+ THROW("Invalid lossless parameters");
+ jpeg_enable_lossless(cinfo, psv, pt);
+ } else if (jpegQual >= 0) {
jpeg_set_quality(cinfo, jpegQual, TRUE);
if (jpegQual >= 96 || flags & TJFLAG_ACCURATEDCT)
cinfo->dct_method = JDCT_ISLOW;
@@ -344,6 +351,9 @@ static void setCompDefaults(struct jpeg_compress_struct *cinfo,
cinfo->comp_info[2].v_samp_factor = 1;
if (cinfo->num_components > 3)
cinfo->comp_info[3].v_samp_factor = tjMCUHeight[subsamp] / 8;
+
+ bailout:
+ return retval;
}
@@ -719,7 +729,10 @@ DLLEXPORT int tjCompress2(tjhandle handle, const unsigned char *srcBuf,
alloc = FALSE; *jpegSize = tjBufSize(width, height, jpegSubsamp);
}
jpeg_mem_dest_tj(cinfo, jpegBuf, jpegSize, alloc);
- setCompDefaults(cinfo, pixelFormat, jpegSubsamp, jpegQual, flags);
+ if (setCompDefaults(cinfo, pixelFormat, jpegSubsamp, jpegQual,
+ flags) == -1) {
+ retval = -1; goto bailout;
+ }
jpeg_start_compress(cinfo, TRUE);
for (i = 0; i < height; i++) {
@@ -817,7 +830,9 @@ DLLEXPORT int tjEncodeYUVPlanes(tjhandle handle, const unsigned char *srcBuf,
else if (flags & TJFLAG_FORCESSE2) PUTENV_S("JSIMD_FORCESSE2", "1");
#endif
- setCompDefaults(cinfo, pixelFormat, subsamp, -1, flags);
+ if (setCompDefaults(cinfo, pixelFormat, subsamp, -1, flags) == -1) {
+ retval = -1; goto bailout;
+ }
/* Execute only the parts of jpeg_start_compress() that we need. If we
were to call the whole jpeg_start_compress() function, then it would try
@@ -1032,7 +1047,9 @@ DLLEXPORT int tjCompressFromYUVPlanes(tjhandle handle,
alloc = FALSE; *jpegSize = tjBufSize(width, height, subsamp);
}
jpeg_mem_dest_tj(cinfo, jpegBuf, jpegSize, alloc);
- setCompDefaults(cinfo, TJPF_RGB, subsamp, jpegQual, flags);
+ if (setCompDefaults(cinfo, TJPF_RGB, subsamp, jpegQual, flags) == -1) {
+ retval = -1; goto bailout;
+ }
cinfo->raw_data_in = TRUE;
jpeg_start_compress(cinfo, TRUE);
diff --git a/turbojpeg.h b/turbojpeg.h
index 570c7c6a..77a90b5f 100644
--- a/turbojpeg.h
+++ b/turbojpeg.h
@@ -370,7 +370,7 @@ enum TJCS {
* The uncompressed source/destination image is stored in bottom-up (Windows,
* OpenGL) order, not top-down (X11) order.
*/
-#define TJFLAG_BOTTOMUP 2
+#define TJFLAG_BOTTOMUP (1 << 1)
/**
* When decompressing an image that was compressed using chrominance
* subsampling, use the fastest chrominance upsampling algorithm available in
@@ -378,7 +378,7 @@ enum TJCS {
* creates a smooth transition between neighboring chrominance components in
* order to reduce upsampling artifacts in the decompressed image.
*/
-#define TJFLAG_FASTUPSAMPLE 256
+#define TJFLAG_FASTUPSAMPLE (1 << 8)
/**
* Disable buffer (re)allocation. If passed to one of the JPEG compression or
* transform functions, this flag will cause those functions to generate an
@@ -386,7 +386,7 @@ enum TJCS {
* attempting to allocate or reallocate that buffer. This reproduces the
* behavior of earlier versions of TurboJPEG.
*/
-#define TJFLAG_NOREALLOC 1024
+#define TJFLAG_NOREALLOC (1 << 10)
/**
* Use the fastest DCT/IDCT algorithm available in the underlying codec. The
* default if this flag is not specified is implementation-specific. For
@@ -395,7 +395,7 @@ enum TJCS {
* only a very slight effect on accuracy, but it uses the accurate algorithm
* when decompressing, because this has been shown to have a larger effect.
*/
-#define TJFLAG_FASTDCT 2048
+#define TJFLAG_FASTDCT (1 << 11)
/**
* Use the most accurate DCT/IDCT algorithm available in the underlying codec.
* The default if this flag is not specified is implementation-specific. For
@@ -404,14 +404,14 @@ enum TJCS {
* only a very slight effect on accuracy, but it uses the accurate algorithm
* when decompressing, because this has been shown to have a larger effect.
*/
-#define TJFLAG_ACCURATEDCT 4096
+#define TJFLAG_ACCURATEDCT (1 << 12)
/**
* Immediately discontinue the current compression/decompression/transform
* operation if the underlying codec throws a warning (non-fatal error). The
* default behavior is to allow the operation to complete unless a fatal error
* is encountered.
*/
-#define TJFLAG_STOPONWARNING 8192
+#define TJFLAG_STOPONWARNING (1 << 13)
/**
* Use progressive entropy coding in JPEG images generated by the compression
* and transform functions. Progressive entropy coding will generally improve
@@ -419,7 +419,7 @@ enum TJCS {
* reduce compression and decompression performance considerably. Can be
* combined with #TJFLAG_ARITHMETIC.
*/
-#define TJFLAG_PROGRESSIVE 16384
+#define TJFLAG_PROGRESSIVE (1 << 14)
/**
* Limit the number of progressive JPEG scans that the decompression and
* transform functions will process. If a progressive JPEG image contains an
@@ -429,7 +429,7 @@ enum TJCS {
* an exploit of the progressive JPEG format described in
* this report.
*/
-#define TJFLAG_LIMITSCANS 32768
+#define TJFLAG_LIMITSCANS (1 << 15)
/**
* Use arithmetic entropy coding in JPEG images generated by the compression
* and transform functions. Arithmetic entropy coding will generally improve
@@ -437,7 +437,23 @@ enum TJCS {
* reduce compression and decompression performance considerably. Can be
* combined with #TJFLAG_PROGRESSIVE.
*/
-#define TJFLAG_ARITHMETIC 65536
+#define TJFLAG_ARITHMETIC (1 << 16)
+/**
+ * Generate a lossless JPEG image when compressing. In most cases, compressing
+ * and decompressing lossless JPEG images is considerably slower than
+ * compressing and decompressing lossy JPEG images. Also note that the
+ * following features are not available with lossless JPEG images:
+ * - Colorspace conversion
+ * - Chrominance subsampling
+ * - JPEG quality selection
+ * - DCT/IDCT algorithm selection
+ * - Progressive entropy coding
+ * - Arithmetic entropy coding
+ * - Compression from/decompression to YUV planar images
+ * - Decompression scaling
+ * - Lossless transformations
+ */
+#define TJFLAG_LOSSLESS (1 << 17)
/**
@@ -527,29 +543,29 @@ enum TJXOP {
* that cannot be transformed will be left in place, which will create
* odd-looking strips on the right or bottom edge of the image.
*/
-#define TJXOPT_PERFECT 1
+#define TJXOPT_PERFECT (1 << 0)
/**
* This option will cause #tjTransform() to discard any partial MCU blocks that
* cannot be transformed.
*/
-#define TJXOPT_TRIM 2
+#define TJXOPT_TRIM (1 << 1)
/**
* This option will enable lossless cropping. See #tjTransform() for more
* information.
*/
-#define TJXOPT_CROP 4
+#define TJXOPT_CROP (1 << 2)
/**
* This option will discard the color data in the input image and produce
* a grayscale output image.
*/
-#define TJXOPT_GRAY 8
+#define TJXOPT_GRAY (1 << 3)
/**
* This option will prevent #tjTransform() from outputting a JPEG image for
* this particular transform (this can be used in conjunction with a custom
* filter to capture the transformed DCT coefficients without transcoding
* them.)
*/
-#define TJXOPT_NOOUTPUT 16
+#define TJXOPT_NOOUTPUT (1 << 4)
/**
* This option will enable progressive entropy coding in the output image
* generated by this particular transform. Progressive entropy coding will
@@ -557,13 +573,13 @@ enum TJXOP {
* default), but it will reduce compression and decompression performance
* considerably. Can be combined with #TJXOPT_ARITHMETIC.
*/
-#define TJXOPT_PROGRESSIVE 32
+#define TJXOPT_PROGRESSIVE (1 << 5)
/**
* This option will prevent #tjTransform() from copying any extra markers
* (including EXIF and ICC profile data) from the source image to the output
* image.
*/
-#define TJXOPT_COPYNONE 64
+#define TJXOPT_COPYNONE (1 << 6)
/**
* This option will enable arithmetic entropy coding in the output image
* generated by this particular transform. Arithmetic entropy coding will
@@ -571,7 +587,7 @@ enum TJXOP {
* default), but it will reduce compression and decompression performance
* considerably. Can be combined with #TJXOPT_PROGRESSIVE.
*/
-#define TJXOPT_ARITHMETIC 128
+#define TJXOPT_ARITHMETIC (1 << 7)
/**
@@ -760,7 +776,13 @@ DLLEXPORT tjhandle tjInitCompress(void);
* "Chrominance subsampling options".)
*
* @param jpegQual the image quality of the generated JPEG image (1 = worst,
- * 100 = best)
+ * 100 = best.) When generating a lossless JPEG image (see #TJFLAG_LOSSLESS),
+ * jpegQual is psv * 10 + Pt, where psv is the
+ * predictor selection value (1-7) and Pt is the point transform
+ * (0-7). A point transform value of 0 is necessary in order to create a fully
+ * lossless JPEG image. (A non-zero point transform value right-shifts the
+ * input samples by the specified number of bits, which is effectively a form
+ * of lossy color quantization.)
*
* @param flags the bitwise OR of one or more of the @ref TJFLAG_ACCURATEDCT
* "flags"
|