This API provides an interface for generating, decoding, and transforming planar YUV and JPEG images in memory.

Macro Definition Documentation

+ + + + +

#define TJ_NUMCS

+ +

The number of JPEG colorspaces.

+ +

@@ -461,7 +490,7 @@ Variables

Disable buffer (re)allocation.

If passed to tjCompress2() or tjTransform(), this flag will cause those functions to generate an error if the JPEG image buffer is invalid or too small rather than attempting to allocate or reallocate that buffer. This reproduces the behavior of earlier versions of TurboJPEG.

Enumeration Type Documentation

+ + + + +

enum TJCS

+ +

JPEG colorspaces.

+ + + + + + +

Enumerator
TJCS_RGB	+ 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. +
TJCS_YCbCr	+ 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. +
TJCS_GRAY	+ 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. +
TJCS_CMYK	+ 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. +
TJCS_YCCK	+ 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. +

+ +

@@ -670,6 +735,10 @@ Variables

ARGB pixel format.

This is the same as TJPF_XRGB, except that when decompressing, the X component is guaranteed to be 0xFF, which can be interpreted as an opaque alpha channel.

+TJPF_CMYK +

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 TJCS_YCCK) and decompressing YCCK JPEG images into CMYK pixels.

@@ -685,7 +754,7 @@ Variables

Enumerator
TJSAMP_444	4:4:4 chrominance subsampling (no chrominance subsampling). @@ -776,7 +845,7 @@ Variables

Decompress a JPEG image to an RGB or grayscale image.

Decompress a JPEG image to an RGB, grayscale, or CMYK image.

Parameters

@@ -1060,26 +1129,23 @@ If you choose option 1, *jpegSize should be set to the size of your - - - - + + + +

handle	a handle to a TurboJPEG decompressor or transformer instance
jpegSize	size of the JPEG image (in bytes)
dstBuf	pointer to an image buffer that will receive the decompressed image. This buffer should normally be `pitch * scaledHeight` bytes in size, where `scaledHeight` can be determined by calling TJSCALED() with the JPEG image height and one of the scaling factors returned by tjGetScalingFactors(). The `dstBuf` pointer may also be used to decompress into a specific region of a larger buffer.
width	desired width (in pixels) of the destination image. If this is different than the width of the JPEG image being decompressed, then TurboJPEG will use scaling in the JPEG decompressor to generate the largest possible image that will fit within the desired width. If `width` is set to 0, then only the height will be considered when determining the scaled image size.
pitch	bytes per line of the destination image. Normally, this is `scaledWidth * tjPixelSize[pixelFormat]` if the decompressed image is unpadded, else `TJPAD(scaledWidth * tjPixelSize[pixelFormat])` if each line of the decompressed image is padded to the nearest 32-bit boundary, as is the case for Windows bitmaps. (NOTE: `scaledWidth` can be determined by calling TJSCALED() with the JPEG image width and one of the scaling factors returned by tjGetScalingFactors().) You can also be clever and use the pitch parameter to skip lines, etc. Setting this parameter to 0 is the equivalent of setting it to `scaledWidth -tjPixelSize[pixelFormat]. - -`
height	`desired height (in pixels) of the destination image. If this is different than the height of the JPEG image being decompressed, then TurboJPEG will use scaling in the JPEG decompressor to generate the largest possible image that will fit within the desired height. If height is set to 0, then only the width will be considered when determining the scaled image size.`
pixelFormat	`pixel format of the destination image (see Pixel formats.)`
flags	`the bitwise OR of one or more of the flags.`
pitch	bytes per line of the destination image. Normally, this is `scaledWidth * tjPixelSize[pixelFormat]` if the decompressed image is unpadded, else `TJPAD(scaledWidth * tjPixelSize[pixelFormat])` if each line of the decompressed image is padded to the nearest 32-bit boundary, as is the case for Windows bitmaps. (NOTE: `scaledWidth` can be determined by calling TJSCALED() with the JPEG image width and one of the scaling factors returned by tjGetScalingFactors().) You can also be clever and use the pitch parameter to skip lines, etc. Setting this parameter to 0 is the equivalent of setting it to `scaledWidth * tjPixelSize[pixelFormat]`.
height	desired height (in pixels) of the destination image. If this is different than the height of the JPEG image being decompressed, then TurboJPEG will use scaling in the JPEG decompressor to generate the largest possible image that will fit within the desired height. If `height` is set to 0, then only the width will be considered when determining the scaled image size.
pixelFormat	pixel format of the destination image (see Pixel formats.)
flags	the bitwise OR of one or more of the flags.

Returns: 0 if successful, or -1 if an error occurred (see tjGetErrorStr().)

Returns: 0 if successful, or -1 if an error occurred (see tjGetErrorStr().)

- + @@ -1112,7 +1178,13 @@ If you choose option 1, *jpegSize should be set to the size of your - + + + + + + + @@ -1130,7 +1202,8 @@ If you choose option 1, *jpegSize should be set to the size of your - + +

DLLEXPORT int DLLCALL tjDecompressHeader2	DLLEXPORT int DLLCALL tjDecompressHeader3	(	tjhandle	handle,	int *	jpegSubsamp	jpegSubsamp,
		int *	jpegColorspace

jpegSize	size of the JPEG image (in bytes)
width	pointer to an integer variable that will receive the width (in pixels) of the JPEG image
height	pointer to an integer variable that will receive the height (in pixels) of the JPEG image
jpegSubsamp	pointer to an integer variable that will receive the level of chrominance subsampling used when compressing the JPEG image (see Chrominance subsampling options.)
jpegSubsamp	pointer to an integer variable that will receive the level of chrominance subsampling used when compressing the JPEG image (see Chrominance subsampling options.)
jpegColorspace	pointer to an integer variable that will receive one of the JPEG colorspace constants, indicating the colorspace of the JPEG image (see JPEG colorspaces.)

@@ -1350,7 +1423,7 @@ If you choose option 1, *jpegSize should be set to the size of your

Free an image buffer previously allocated by TurboJPEG.

You should always use this function to free JPEG destination buffer(s) that were automatically (re)allocated by tjCompress2() or tjTransform() or that were manually allocated using tjAlloc().

Parameters

diff --git a/doc/html/search/all_74.js b/doc/html/search/all_74.js index 01c414a..4aec528 100644 --- a/doc/html/search/all_74.js +++ b/doc/html/search/all_74.js @@ -1,5 +1,6 @@ var searchData= [ + ['tj_5fnumcs',['TJ_NUMCS',['../group___turbo_j_p_e_g.html#ga39f57a6fb02d9cf32e7b6890099b5a71',1,'turbojpeg.h']]], ['tj_5fnumpf',['TJ_NUMPF',['../group___turbo_j_p_e_g.html#ga7010a4402f54a45ba822ad8675a4655e',1,'turbojpeg.h']]], ['tj_5fnumsamp',['TJ_NUMSAMP',['../group___turbo_j_p_e_g.html#ga5ef3d169162ce77ce348e292a0b7477c',1,'turbojpeg.h']]], ['tj_5fnumxop',['TJ_NUMXOP',['../group___turbo_j_p_e_g.html#ga0f6dbd18adf38b7d46ac547f0f4d562c',1,'turbojpeg.h']]], @@ -8,8 +9,14 @@ var searchData= ['tjbufsize',['tjBufSize',['../group___turbo_j_p_e_g.html#gaccc5bca7f12fcdcc302e6e1c6d4b311b',1,'turbojpeg.h']]], ['tjbufsizeyuv2',['tjBufSizeYUV2',['../group___turbo_j_p_e_g.html#gaf451664a62c1f6c7cc5a6401f32908c9',1,'turbojpeg.h']]], ['tjcompress2',['tjCompress2',['../group___turbo_j_p_e_g.html#gaba62b7a98f960839b588579898495cf2',1,'turbojpeg.h']]], + ['tjcs',['TJCS',['../group___turbo_j_p_e_g.html#ga4f83ad3368e0e29d1957be0efa7c3720',1,'turbojpeg.h']]], + ['tjcs_5fcmyk',['TJCS_CMYK',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720a6c8b636152ac8195b869587db315ee53',1,'turbojpeg.h']]], + ['tjcs_5fgray',['TJCS_GRAY',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720ab3e7d6a87f695e45b81c1b5262b5a50a',1,'turbojpeg.h']]], + ['tjcs_5frgb',['TJCS_RGB',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720a677cb7ccb85c4038ac41964a2e09e555',1,'turbojpeg.h']]], + ['tjcs_5fycbcr',['TJCS_YCbCr',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720a7389b8f65bb387ffedce3efd0d78ec75',1,'turbojpeg.h']]], + ['tjcs_5fycck',['TJCS_YCCK',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720a53839e0fe867b76b58d16b0a1a7c598e',1,'turbojpeg.h']]], ['tjdecompress2',['tjDecompress2',['../group___turbo_j_p_e_g.html#gada69cc6443d1bb493b40f1626259e5e9',1,'turbojpeg.h']]], - ['tjdecompressheader2',['tjDecompressHeader2',['../group___turbo_j_p_e_g.html#gac5675fceb7997b385516cdffdb34e6aa',1,'turbojpeg.h']]], + ['tjdecompressheader3',['tjDecompressHeader3',['../group___turbo_j_p_e_g.html#gacd0fac3af74b3511d39b4781b7103086',1,'turbojpeg.h']]], ['tjdecompresstoyuv2',['tjDecompressToYUV2',['../group___turbo_j_p_e_g.html#ga7c08b340ad7f8e85d407bd9e81d44d07',1,'turbojpeg.h']]], ['tjdestroy',['tjDestroy',['../group___turbo_j_p_e_g.html#ga674adee917b95ad4a896f1ba39e12540',1,'turbojpeg.h']]], ['tjencodeyuv3',['tjEncodeYUV3',['../group___turbo_j_p_e_g.html#ga0a5ffbf7cb58a5b6a8201114fe889360',1,'turbojpeg.h']]], @@ -39,6 +46,7 @@ var searchData= ['tjpf_5fbgr',['TJPF_BGR',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aab10624437fb8ef495a0b153e65749839',1,'turbojpeg.h']]], ['tjpf_5fbgra',['TJPF_BGRA',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aac037ff1845cf9b74bb81a3659c2b9fb4',1,'turbojpeg.h']]], ['tjpf_5fbgrx',['TJPF_BGRX',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa2a1fbf569ca79897eae886e3376ca4c8',1,'turbojpeg.h']]], + ['tjpf_5fcmyk',['TJPF_CMYK',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa7f5100ec44c91994e243f1cf55553f8b',1,'turbojpeg.h']]], ['tjpf_5fgray',['TJPF_GRAY',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa5431b54b015337705f13118073711a1a',1,'turbojpeg.h']]], ['tjpf_5frgb',['TJPF_RGB',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa7ce93230bff449518ce387c17e6ed37c',1,'turbojpeg.h']]], ['tjpf_5frgba',['TJPF_RGBA',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa88d2e88fab67f6503cf972e14851cc12',1,'turbojpeg.h']]], diff --git a/doc/html/search/enums_74.js b/doc/html/search/enums_74.js index 20bd4db..276aa24 100644 --- a/doc/html/search/enums_74.js +++ b/doc/html/search/enums_74.js @@ -1,5 +1,6 @@ var searchData= [ + ['tjcs',['TJCS',['../group___turbo_j_p_e_g.html#ga4f83ad3368e0e29d1957be0efa7c3720',1,'turbojpeg.h']]], ['tjpf',['TJPF',['../group___turbo_j_p_e_g.html#gac916144e26c3817ac514e64ae5d12e2a',1,'turbojpeg.h']]], ['tjsamp',['TJSAMP',['../group___turbo_j_p_e_g.html#ga1d047060ea80bb9820d540bb928e9074',1,'turbojpeg.h']]], ['tjxop',['TJXOP',['../group___turbo_j_p_e_g.html#ga2de531af4e7e6c4f124908376b354866',1,'turbojpeg.h']]] diff --git a/doc/html/search/enumvalues_74.js b/doc/html/search/enumvalues_74.js index 16e7e15..7dc2f8d 100644 --- a/doc/html/search/enumvalues_74.js +++ b/doc/html/search/enumvalues_74.js @@ -1,10 +1,16 @@ var searchData= [ + ['tjcs_5fcmyk',['TJCS_CMYK',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720a6c8b636152ac8195b869587db315ee53',1,'turbojpeg.h']]], + ['tjcs_5fgray',['TJCS_GRAY',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720ab3e7d6a87f695e45b81c1b5262b5a50a',1,'turbojpeg.h']]], + ['tjcs_5frgb',['TJCS_RGB',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720a677cb7ccb85c4038ac41964a2e09e555',1,'turbojpeg.h']]], + ['tjcs_5fycbcr',['TJCS_YCbCr',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720a7389b8f65bb387ffedce3efd0d78ec75',1,'turbojpeg.h']]], + ['tjcs_5fycck',['TJCS_YCCK',['../group___turbo_j_p_e_g.html#gga4f83ad3368e0e29d1957be0efa7c3720a53839e0fe867b76b58d16b0a1a7c598e',1,'turbojpeg.h']]], ['tjpf_5fabgr',['TJPF_ABGR',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa1ba1a7f1631dbeaa49a0a85fc4a40081',1,'turbojpeg.h']]], ['tjpf_5fargb',['TJPF_ARGB',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aae8f846ed9d9de99b6e1dfe448848765c',1,'turbojpeg.h']]], ['tjpf_5fbgr',['TJPF_BGR',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aab10624437fb8ef495a0b153e65749839',1,'turbojpeg.h']]], ['tjpf_5fbgra',['TJPF_BGRA',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aac037ff1845cf9b74bb81a3659c2b9fb4',1,'turbojpeg.h']]], ['tjpf_5fbgrx',['TJPF_BGRX',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa2a1fbf569ca79897eae886e3376ca4c8',1,'turbojpeg.h']]], + ['tjpf_5fcmyk',['TJPF_CMYK',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa7f5100ec44c91994e243f1cf55553f8b',1,'turbojpeg.h']]], ['tjpf_5fgray',['TJPF_GRAY',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa5431b54b015337705f13118073711a1a',1,'turbojpeg.h']]], ['tjpf_5frgb',['TJPF_RGB',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa7ce93230bff449518ce387c17e6ed37c',1,'turbojpeg.h']]], ['tjpf_5frgba',['TJPF_RGBA',['../group___turbo_j_p_e_g.html#ggac916144e26c3817ac514e64ae5d12e2aa88d2e88fab67f6503cf972e14851cc12',1,'turbojpeg.h']]], diff --git a/doc/html/search/functions_74.js b/doc/html/search/functions_74.js index cedfc7a..8f92c26 100644 --- a/doc/html/search/functions_74.js +++ b/doc/html/search/functions_74.js @@ -5,7 +5,7 @@ var searchData= ['tjbufsizeyuv2',['tjBufSizeYUV2',['../group___turbo_j_p_e_g.html#gaf451664a62c1f6c7cc5a6401f32908c9',1,'turbojpeg.h']]], ['tjcompress2',['tjCompress2',['../group___turbo_j_p_e_g.html#gaba62b7a98f960839b588579898495cf2',1,'turbojpeg.h']]], ['tjdecompress2',['tjDecompress2',['../group___turbo_j_p_e_g.html#gada69cc6443d1bb493b40f1626259e5e9',1,'turbojpeg.h']]], - ['tjdecompressheader2',['tjDecompressHeader2',['../group___turbo_j_p_e_g.html#gac5675fceb7997b385516cdffdb34e6aa',1,'turbojpeg.h']]], + ['tjdecompressheader3',['tjDecompressHeader3',['../group___turbo_j_p_e_g.html#gacd0fac3af74b3511d39b4781b7103086',1,'turbojpeg.h']]], ['tjdecompresstoyuv2',['tjDecompressToYUV2',['../group___turbo_j_p_e_g.html#ga7c08b340ad7f8e85d407bd9e81d44d07',1,'turbojpeg.h']]], ['tjdestroy',['tjDestroy',['../group___turbo_j_p_e_g.html#ga674adee917b95ad4a896f1ba39e12540',1,'turbojpeg.h']]], ['tjencodeyuv3',['tjEncodeYUV3',['../group___turbo_j_p_e_g.html#ga0a5ffbf7cb58a5b6a8201114fe889360',1,'turbojpeg.h']]], diff --git a/doc/html/structtjtransform.html b/doc/html/structtjtransform.html index 33e3724..9f2939a 100644 --- a/doc/html/structtjtransform.html +++ b/doc/html/structtjtransform.html @@ -108,7 +108,7 @@ Data Fields - +

buffer	address of the buffer to free
	Arbitrary data that can be accessed within the body of the callback function. More...

int(*	customFilter )(short coeffs, tjregion arrayRegion, tjregion planeRegion, int componentIndex, int transformIndex, struct tjtransform transform)
	A callback function that can be used to modify the DCT coefficients after they are losslessly transformed but before they are transcoded to a new JPEG file. More...
	A callback function that can be used to modify the DCT coefficients after they are losslessly transformed but before they are transcoded to a new JPEG image. More...

Detailed Description

@@ -124,7 +124,7 @@ Data Fields

A callback function that can be used to modify the DCT coefficients after they are losslessly transformed but before they are transcoded to a new JPEG file.

A callback function that can be used to modify the DCT coefficients after they are losslessly transformed but before they are transcoded to a new JPEG image.

This allows for custom filters or other transformations to be applied in the frequency domain.

Parameters

-- cgit v1.2.3

handle	a handle to a TurboJPEG compressor or transformer instance
srcBuf	pointer to an image buffer containing RGB or grayscale pixels to be compressed
srcBuf	pointer to an image buffer containing RGB, grayscale, or CMYK pixels to be compressed
width	width (in pixels) of the source image
pitch	bytes per line of the source image. Normally, this should be `width * tjPixelSize[pixelFormat]` if the image is unpadded, or `TJPAD(width * tjPixelSize[pixelFormat])` if each line of the image is padded to the nearest 32-bit boundary, as is the case for Windows bitmaps. You can also be clever and use this parameter to skip lines, etc. Setting this parameter to 0 is the equivalent of setting it to `width * tjPixelSize[pixelFormat]`.
height	height (in pixels) of the source image