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

- +

anonymous enum enum TJPF

Pixel formats.

Enumerator:

- - - - - - - @@ -483,48 +523,87 @@ static const int - +

TJ_RGB

TJPF_RGB

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 address within each pixel.

TJ_BGR

TJPF_BGR

BGR pixel format.

The red, green, and blue components in the image are stored in 3-byte pixels in the order B, G, R from lowest to highest byte address within each pixel.

TJ_RGBX

TJPF_RGBX

RGBX pixel format.

The red, green, and blue components in the image are stored in 4-byte pixels in the order R, G, B from lowest to highest byte address within each pixel.

TJ_BGRX

TJPF_BGRX

BGRX pixel format.

The red, green, and blue components in the image are stored in 4-byte pixels in the order B, G, R from lowest to highest byte address within each pixel.

TJ_XBGR

TJPF_XBGR

XBGR pixel format.

The red, green, and blue components in the image are stored in 4-byte pixels in the order R, G, B from highest to lowest byte address within each pixel.

TJ_XRGB

TJPF_XRGB

XRGB pixel format.

The red, green, and blue components in the image are stored in 4-byte pixels in the order B, G, R from highest to lowest byte address within each pixel.

TJ_GRAY

TJPF_GRAY

Grayscale pixel format.

Each 1-byte pixel represents a luminance (brightness) level from 0 to 255.

+ +

+ + + + +

enum TJSAMP

+ +

Chrominance subsampling options.

When an image is converted from the RGB to the YCbCr colorspace as part of the JPEG compression process, some of the Cb and Cr (chrominance) components can be discarded or averaged together to produce a smaller image with little perceptible loss of image clarity (the human eye is more sensitive to small changes in brightness than small changes in color.) This is called "chrominance subsampling".

Enumerator:

+ + + + + +

TJSAMP_444	+ 4:4:4 chrominance subsampling (no chrominance subsampling). + The JPEG or YUV image will contain one chrominance component for every pixel in the source image. +
TJSAMP_422	+ 4:2:2 chrominance subsampling. + The JPEG or YUV image will contain one chrominance component for every 2x1 block of pixels in the source image. +
TJSAMP_420	+ 4:2:0 chrominance subsampling. + The JPEG or YUV image will contain one chrominance component for every 2x2 block of pixels in the source image. +
TJSAMP_GRAY	+ Grayscale. + The JPEG or YUV image will contain no chrominance components. +
TJSAMP_440	+ 4:4:0 chrominance subsampling. + The JPEG or YUV image will contain one chrominance component for every 1x2 block of pixels in the source image. +

+ +

- +

anonymous enum enum TJXOP

Transform operations for tjTransform.

Transform operations for tjTransform()

Enumerator:

- - - - - - - -

TJXFORM_NONE	+
TJXOP_NONE	Do not transform the position of the image pixels.
TJXFORM_HFLIP	+
TJXOP_HFLIP	Flip (mirror) image horizontally. - This transform is imperfect if there are any partial MCU blocks on the right edge (see TJXFORM_PERFECT.) + This transform is imperfect if there are any partial MCU blocks on the right edge (see TJXOPT_PERFECT.)
TJXFORM_VFLIP	+
TJXOP_VFLIP	Flip (mirror) image vertically. - This transform is imperfect if there are any partial MCU blocks on the bottom edge (see TJXFORM_PERFECT.) + This transform is imperfect if there are any partial MCU blocks on the bottom edge (see TJXOPT_PERFECT.)
TJXFORM_TRANSPOSE	+
TJXOP_TRANSPOSE	Transpose image (flip/mirror along upper left to lower right axis.) This transform is always perfect.
TJXFORM_TRANSVERSE	- Transverse transpose image (flip/mirror along upper right to lower left axis.) This transform is imperfect if there are any partial MCU blocks in the image (see TJXFORM_PERFECT.) +
TJXOP_TRANSVERSE	+ Transverse transpose image (flip/mirror along upper right to lower left axis.) This transform is imperfect if there are any partial MCU blocks in the image (see TJXOPT_PERFECT.)
TJXFORM_ROT90	+
TJXOP_ROT90	Rotate image clockwise by 90 degrees. - This transform is imperfect if there are any partial MCU blocks on the bottom edge (see TJXFORM_PERFECT.) + This transform is imperfect if there are any partial MCU blocks on the bottom edge (see TJXOPT_PERFECT.)
TJXFORM_ROT180	+
TJXOP_ROT180	Rotate image 180 degrees. - This transform is imperfect if there are any partial MCU blocks in the image (see TJXFORM_PERFECT.) + This transform is imperfect if there are any partial MCU blocks in the image (see TJXOPT_PERFECT.)
TJXFORM_ROT270	+
TJXOP_ROT270	Rotate image counter-clockwise by 90 degrees. - This transform is imperfect if there are any partial MCU blocks on the right edge (see TJXFORM_PERFECT.) + This transform is imperfect if there are any partial MCU blocks on the right edge (see TJXOPT_PERFECT.)

width

width of the image (in pixels)

height

height of the image (in pixels)

jpegSubsamp

level of chrominance subsampling in the image (see Chrominance subsampling options.)

jpegSubsamp

level of chrominance subsampling in the image (see Chrominance subsampling options.)

@@ -701,17 +780,17 @@ static const int widthwidth (in pixels) of the source image pitchbytes 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]. heightheight (in pixels) of the source image - pixelFormatpixel format of the source image (see Pixel formats.) + pixelFormatpixel format of the source image (see Pixel formats.) jpegBufaddress of a pointer to an image buffer that will receive the JPEG image. TurboJPEG has the ability to reallocate the JPEG buffer to accommodate the size of the JPEG image. Thus, you can choose to:

pre-allocate the JPEG buffer with an arbitrary size and let TurboJPEG grow the buffer as needed,
set *jpegBuf to NULL to tell TurboJPEG to allocate the buffer for you, or
pre-allocate the buffer to a "worst case" size determined by calling TJBUFSIZE(). This should ensure that the buffer never has to be re-allocated (setting the TJ_NOREALLOC flag guarantees this.)
pre-allocate the buffer to a "worst case" size determined by calling TJBUFSIZE(). This should ensure that the buffer never has to be re-allocated (setting TJFLAG_NOREALLOC guarantees this.)

-If you choose option 1 or 3, *jpegSize should be set to the size of your pre-allocated buffer. In any case, unless you have set the TJ_NOREALLOC flag, you should always check *jpegBuf upon return from this function, as it may have changed. +If you choose option 1 or 3, *jpegSize should be set to the size of your pre-allocated buffer. In any case, unless you have set TJFLAG_NOREALLOC, you should always check *jpegBuf upon return from this function, as it may have changed. jpegSizepointer to an unsigned long variable which holds the size of the JPEG image buffer. If *jpegBuf points to a pre-allocated buffer, then *jpegSize should be set to the size of the buffer. Upon return, *jpegSize will contain the size of the JPEG image (in bytes.) - jpegSubsampthe level of chrominance subsampling to be used when generating the JPEG image (see Chrominance subsampling options.) + jpegSubsampthe level of chrominance subsampling to be used when generating the JPEG image (see Chrominance subsampling options.) jpegQualthe image quality of the generated JPEG image (1 = worst, 100 = best) - flagsthe bitwise OR of one or more of the flags. + flagsthe bitwise OR of one or more of the flags. @@ -796,8 +875,8 @@ If you choose option 1 or 3, *jpegSize should be set to the size of widthdesired width (in pixels) of the destination image. If this is smaller 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. pitchbytes 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]. heightdesired height (in pixels) of the destination image. If this is smaller 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. - pixelFormatpixel format of the destination image (see Pixel formats.) - flagsthe bitwise OR of one or more of the flags. + pixelFormatpixel format of the destination image (see Pixel formats.) + flagsthe bitwise OR of one or more of the flags. @@ -862,7 +941,7 @@ If you choose option 1 or 3, *jpegSize should be set to the size of jpegSizesize of the JPEG image (in bytes) widthpointer to an integer variable which will receive the width (in pixels) of the JPEG image heightpointer to an integer variable which will receive the height (in pixels) of the JPEG image - jpegSubsamppointer to an integer variable which will receive the level of chrominance subsampling used when compressing the JPEG image (see Chrominance subsampling options.) + jpegSubsamppointer to an integer variable which will receive the level of chrominance subsampling used when compressing the JPEG image (see Chrominance subsampling options.) @@ -921,7 +1000,7 @@ If you choose option 1 or 3, *jpegSize should be set to the size of jpegBufpointer to a buffer containing the JPEG image to decompress jpegSizesize of the JPEG image (in bytes) dstBufpointer to an image buffer which will receive the YUV image. Use TJBUFSIZEYUV to determine the appropriate size for this buffer based on the image width, height, and level of subsampling. - flagsthe bitwise OR of one or more of the flags. + flagsthe bitwise OR of one or more of the flags. @@ -1031,10 +1110,10 @@ If you choose option 1 or 3, *jpegSize should be set to the size of widthwidth (in pixels) of the source image pitchbytes 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]. heightheight (in pixels) of the source image - pixelFormatpixel format of the source image (see Pixel formats.) + pixelFormatpixel format of the source image (see Pixel formats.) dstBufpointer to an image buffer which will receive the YUV image. Use TJBUFSIZEYUV() to determine the appropriate size for this buffer based on the image width, height, and level of chrominance subsampling. - subsampthe level of chrominance subsampling to be used when generating the YUV image (see Chrominance subsampling options.) - flagsthe bitwise OR of one or more of the flags. + subsampthe level of chrominance subsampling to be used when generating the YUV image (see Chrominance subsampling options.) + flagsthe bitwise OR of one or more of the flags. @@ -1220,12 +1299,12 @@ If you choose option 1 or 3, *jpegSize should be set to the size of dstBufspointer to an array of n image buffers. dstBufs[i] will receive a JPEG image that has been transformed using the parameters in transforms[i]. TurboJPEG has the ability to reallocate the JPEG buffer to accommodate the size of the JPEG image. Thus, you can choose to:

pre-allocate the JPEG buffer with an arbitrary size and let TurboJPEG grow the buffer as needed,
set dstBufs[i] to NULL to tell TurboJPEG to allocate the buffer for you, or
pre-allocate the buffer to a "worst case" size determined by calling TJBUFSIZE() with the cropped width and height. This should ensure that the buffer never has to be re-allocated (setting the TJ_NOREALLOC flag guarantees this.)
pre-allocate the buffer to a "worst case" size determined by calling TJBUFSIZE() with the cropped width and height. This should ensure that the buffer never has to be re-allocated (setting TJFLAG_NOREALLOC guarantees this.)

-If you choose option 1 or 3, dstSizes[i] should be set to the size of your pre-allocated buffer. In any case, unless you have set the TJ_NOREALLOC flag, you should always check dstBufs[i] upon return from this function, as it may have changed. +If you choose option 1 or 3, dstSizes[i] should be set to the size of your pre-allocated buffer. In any case, unless you have set TJFLAG_NOREALLOC, you should always check dstBufs[i] upon return from this function, as it may have changed. dstSizespointer to an array of n unsigned long variables which will receive the actual sizes (in bytes) of each transformed JPEG image. If dstBufs[i] points to a pre-allocated buffer, then dstSizes[i] should be set to the size of the buffer. Upon return, dstSizes[i] will contain the size of the JPEG image (in bytes.) transformspointer to an array of n tjtransform structures, each of which specifies the transform parameters and/or cropping region for the corresponding transformed output image. - flagsthe bitwise OR of one or more of the flags. + flagsthe bitwise OR of one or more of the flags. @@ -1308,6 +1387,21 @@ If you choose option 1 or 3, dstSizes[i] should be set to the size

16x16 for 4:2:0

TJ_444	- 4:4:4 chrominance subsampling (no chrominance subsampling). - The JPEG or YUV image will contain one chrominance component for every pixel in the source image. -
TJ_422	- 4:2:2 chrominance subsampling. - The JPEG or YUV image will contain one chrominance component for every 2x1 block of pixels in the source image. -
TJ_420	- 4:2:0 chrominance subsampling. - The JPEG or YUV image will contain one chrominance component for every 2x2 block of pixels in the source image. -
TJ_GRAYSCALE	- Grayscale. - The JPEG or YUV image will contain no chrominance components. -
TJ_440	- 4:4:0 chrominance subsampling. - The JPEG or YUV image will contain one chrominance component for every 1x2 block of pixels in the source image. -

Data Fields
-int	num
	Numerator.
-int	denom
	Denominator.
int	num
	Numerator.
int	denom
	Denominator.

Data Fields
-tjregion	r
	Cropping region.
-int	op
	One of the transform operations (see Transform operations.)
-int	options
	The bitwise OR of one of more of the transform options (see Transform options.)
tjregion	r
	Cropping region.
int	op
	One of the transform operations.
int	options
	The bitwise OR of one of more of the transform options.

Defines

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