java.lang.Object
- org.libjpegturbo.turbojpeg.TJ

public final class TJ
extends java.lang.Object

TurboJPEG utility class (cannot be instantiated)

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`CS_CMYK`	CMYK colorspace.
`static int`	`CS_GRAY`	Grayscale colorspace.
`static int`	`CS_RGB`	RGB colorspace.
`static int`	`CS_YCbCr`	YCbCr colorspace.
`static int`	`CS_YCCK`	YCCK colorspace.
`static int`	`ERR_FATAL`	The error was fatal and non-recoverable.
`static int`	`ERR_WARNING`	The error was non-fatal and recoverable, but the destination image may still be corrupt.
`static int`	`FLAG_ACCURATEDCT`	Deprecated. Use `PARAM_FASTDCT` instead.
`static int`	`FLAG_BOTTOMUP`	Deprecated. Use `PARAM_BOTTOMUP` instead.
`static int`	`FLAG_FASTDCT`	Deprecated. Use `PARAM_FASTDCT` instead.
`static int`	`FLAG_FASTUPSAMPLE`	Deprecated. Use `PARAM_FASTUPSAMPLE` instead.
`static int`	`FLAG_LIMITSCANS`	Deprecated. Use `PARAM_SCANLIMIT` instead.
`static int`	`FLAG_PROGRESSIVE`	Deprecated. Use `PARAM_PROGRESSIVE` instead.
`static int`	`FLAG_STOPONWARNING`	Deprecated. Use `PARAM_STOPONWARNING` instead.
`static int`	`NUMCS`	The number of JPEG colorspaces
`static int`	`NUMERR`	The number of error codes
`static int`	`NUMPF`	The number of pixel formats
`static int`	`NUMSAMP`	The number of chrominance subsampling options
`static int`	`PARAM_ARITHMETIC`	Arithmetic entropy coding
`static int`	`PARAM_BOTTOMUP`	Row order in packed-pixel source/destination images
`static int`	`PARAM_COLORSPACE`	JPEG colorspace
`static int`	`PARAM_DENSITYUNITS`	JPEG pixel density units
`static int`	`PARAM_FASTDCT`	DCT/IDCT algorithm [lossy compression and decompression]
`static int`	`PARAM_FASTUPSAMPLE`	Chrominance upsampling algorithm [lossy decompression only]
`static int`	`PARAM_JPEGHEIGHT`	JPEG height (in pixels) [decompression only, read-only]
`static int`	`PARAM_JPEGWIDTH`	JPEG width (in pixels) [decompression only, read-only]
`static int`	`PARAM_LOSSLESS`	Lossless JPEG
`static int`	`PARAM_LOSSLESSPSV`	Lossless JPEG predictor selection value (PSV)
`static int`	`PARAM_LOSSLESSPT`	Lossless JPEG point transform (Pt)
`static int`	`PARAM_MAXMEMORY`	Memory limit for intermediate buffers
`static int`	`PARAM_MAXPIXELS`	Image size limit [decompression, lossless transformation]
`static int`	`PARAM_OPTIMIZE`	Optimized baseline entropy coding [lossy compression only]
`static int`	`PARAM_PRECISION`	JPEG data precision (bits per sample) [decompression only, read-only]
`static int`	`PARAM_PROGRESSIVE`	Progressive entropy coding
`static int`	`PARAM_QUALITY`	Perceptual quality of lossy JPEG images [compression only]
`static int`	`PARAM_RESTARTBLOCKS`	JPEG restart marker interval in MCU blocks (lossy) or samples (lossless) [compression only]
`static int`	`PARAM_RESTARTROWS`	JPEG restart marker interval in MCU rows (lossy) or sample rows (lossless) [compression only]
`static int`	`PARAM_SCANLIMIT`	Progressive JPEG scan limit for lossy JPEG images [decompression, lossless transformation]
`static int`	`PARAM_STOPONWARNING`	Error handling behavior
`static int`	`PARAM_SUBSAMP`	Chrominance subsampling level
`static int`	`PARAM_XDENSITY`	JPEG horizontal pixel density
`static int`	`PARAM_YDENSITY`	JPEG vertical pixel density
`static int`	`PF_ABGR`	ABGR pixel format.
`static int`	`PF_ARGB`	ARGB pixel format.
`static int`	`PF_BGR`	BGR pixel format.
`static int`	`PF_BGRA`	BGRA pixel format.
`static int`	`PF_BGRX`	BGRX pixel format.
`static int`	`PF_CMYK`	CMYK pixel format.
`static int`	`PF_GRAY`	Grayscale pixel format.
`static int`	`PF_RGB`	RGB pixel format.
`static int`	`PF_RGBA`	RGBA pixel format.
`static int`	`PF_RGBX`	RGBX pixel format.
`static int`	`PF_XBGR`	XBGR pixel format.
`static int`	`PF_XRGB`	XRGB pixel format.
`static int`	`SAMP_411`	4:1:1 chrominance subsampling.
`static int`	`SAMP_420`	4:2:0 chrominance subsampling.
`static int`	`SAMP_422`	4:2:2 chrominance subsampling.
`static int`	`SAMP_440`	4:4:0 chrominance subsampling.
`static int`	`SAMP_441`	4:4:1 chrominance subsampling.
`static int`	`SAMP_444`	4:4:4 chrominance subsampling (no chrominance subsampling).
`static int`	`SAMP_GRAY`	Grayscale.
`static int`	`SAMP_UNKNOWN`	Unknown subsampling.
`static java.awt.Rectangle`	`UNCROPPED`	A `java.awt.Rectangle` instance that specifies no cropping
`static TJScalingFactor`	`UNSCALED`	A `TJScalingFactor` instance that specifies a scaling factor of 1/1 (no scaling)

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static int`	`bufSize(int width, int height, int jpegSubsamp)`	Returns the maximum size of the buffer (in bytes) required to hold a JPEG image with the given width, height, and level of chrominance subsampling.
`static int`	`bufSizeYUV(int width, int align, int height, int subsamp)`	Returns the size of the buffer (in bytes) required to hold a unified planar YUV image with the given width, height, and level of chrominance subsampling.
`static int`	`getAlphaOffset(int pixelFormat)`	For the given pixel format, returns the number of samples that the alpha component is offset from the start of the pixel.
`static int`	`getBlueOffset(int pixelFormat)`	For the given pixel format, returns the number of samples that the blue component is offset from the start of the pixel.
`static int`	`getGreenOffset(int pixelFormat)`	For the given pixel format, returns the number of samples that the green component is offset from the start of the pixel.
`static int`	`getMCUHeight(int subsamp)`	Returns the MCU block height for the given level of chrominance subsampling.
`static int`	`getMCUWidth(int subsamp)`	Returns the MCU block width for the given level of chrominance subsampling.
`static int`	`getPixelSize(int pixelFormat)`	Returns the pixel size (in samples) for the given pixel format.
`static int`	`getRedOffset(int pixelFormat)`	For the given pixel format, returns the number of samples that the red component is offset from the start of the pixel.
`static TJScalingFactor[]`	`getScalingFactors()`	Returns a list of fractional scaling factors that the JPEG decompressor supports.
`static int`	`planeHeight(int componentID, int height, int subsamp)`	Returns the plane height of a YUV image plane with the given parameters.
`static int`	`planeSizeYUV(int componentID, int width, int stride, int height, int subsamp)`	Returns the size of the buffer (in bytes) required to hold a YUV image plane with the given parameters.
`static int`	`planeWidth(int componentID, int width, int subsamp)`	Returns the plane width of a YUV image plane with the given parameters.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - NUMSAMP
```
public static final int NUMSAMP
```
    The number of chrominance subsampling options
    
    See Also:
    
    Constant Field Values
  - SAMP_444
```
public static final int SAMP_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.
    
    See Also:
    
    Constant Field Values
  - SAMP_422
```
public static final int SAMP_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.
    
    See Also:
    
    Constant Field Values
  - SAMP_420
```
public static final int SAMP_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.
    
    See Also:
    
    Constant Field Values
  - SAMP_GRAY
```
public static final int SAMP_GRAY
```
    Grayscale. The JPEG or YUV image will contain no chrominance components.
    
    See Also:
    
    Constant Field Values
  - SAMP_440
```
public static final int SAMP_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. Note that 4:4:0 subsampling is not fully accelerated in libjpeg-turbo.
    
    See Also:
    
    Constant Field Values
  - SAMP_411
```
public static final int SAMP_411
```
    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.
    
    See Also:
    
    Constant Field Values
  - SAMP_441
```
public static final int SAMP_441
```
    4:4:1 chrominance subsampling. The JPEG or YUV image will contain one chrominance component for every 1x4 block of pixels in the source image. JPEG images compressed with 4:4:1 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, 4:4:1 is better able to reproduce sharp vertical features. Note that 4:4:1 subsampling is not fully accelerated in libjpeg-turbo.
    
    See Also:
    
    Constant Field Values
  - SAMP_UNKNOWN
```
public static final int SAMP_UNKNOWN
```
    Unknown subsampling. The JPEG image uses an unusual type of chrominance subsampling. Such images can be decompressed into packed-pixel images, but they cannot be
    
    decompressed into planar YUV images,
    losslessly transformed if TJTransform.OPT_CROP is specified, or
    partially decompressed using a cropping region.
    See Also:
    
    Constant Field Values
  - NUMPF
```
public static final int NUMPF
```
    The number of pixel formats
    
    See Also:
    
    Constant Field Values
  - PF_RGB
```
public static final int PF_RGB
```
    RGB pixel format. The red, green, and blue components in the image are stored in 3-sample pixels in the order R, G, B from lowest to highest memory address within each pixel.
    
    See Also:
    
    Constant Field Values
  - PF_BGR
```
public static final int PF_BGR
```
    BGR pixel format. The red, green, and blue components in the image are stored in 3-sample pixels in the order B, G, R from lowest to highest memory address within each pixel.
    
    See Also:
    
    Constant Field Values
  - PF_RGBX
```
public static final int PF_RGBX
```
    RGBX pixel format. The red, green, and blue components in the image are stored in 4-sample pixels in the order R, G, B from lowest to highest memory address within each pixel. The X component is ignored when compressing and undefined when decompressing.
    
    See Also:
    
    Constant Field Values
  - PF_BGRX
```
public static final int PF_BGRX
```
    BGRX pixel format. The red, green, and blue components in the image are stored in 4-sample pixels in the order B, G, R from lowest to highest memory address within each pixel. The X component is ignored when compressing and undefined when decompressing.
    
    See Also:
    
    Constant Field Values
  - PF_XBGR
```
public static final int PF_XBGR
```
    XBGR pixel format. The red, green, and blue components in the image are stored in 4-sample pixels in the order R, G, B from highest to lowest memory address within each pixel. The X component is ignored when compressing and undefined when decompressing.
    
    See Also:
    
    Constant Field Values
  - PF_XRGB
```
public static final int PF_XRGB
```
    XRGB pixel format. The red, green, and blue components in the image are stored in 4-sample pixels in the order B, G, R from highest to lowest memory address within each pixel. The X component is ignored when compressing and undefined when decompressing.
    
    See Also:
    
    Constant Field Values
  - PF_GRAY
```
public static final int PF_GRAY
```
    Grayscale pixel format. Each 1-sample pixel represents a luminance (brightness) level from 0 to the maximum sample value (255 for 8-bit samples, 4095 for 12-bit samples, and 65535 for 16-bit samples.)
    
    See Also:
    
    Constant Field Values
  - PF_RGBA
```
public static final int PF_RGBA
```
    RGBA pixel format. This is the same as PF_RGBX, except that when decompressing, the X component is guaranteed to be equal to the maximum sample value, which can be interpreted as an opaque alpha channel.
    
    See Also:
    
    Constant Field Values
  - PF_BGRA
```
public static final int PF_BGRA
```
    BGRA pixel format. This is the same as PF_BGRX, except that when decompressing, the X component is guaranteed to be equal to the maximum sample value, which can be interpreted as an opaque alpha channel.
    
    See Also:
    
    Constant Field Values
  - PF_ABGR
```
public static final int PF_ABGR
```
    ABGR pixel format. This is the same as PF_XBGR, except that when decompressing, the X component is guaranteed to be equal to the maximum sample value, which can be interpreted as an opaque alpha channel.
    
    See Also:
    
    Constant Field Values
  - PF_ARGB
```
public static final int PF_ARGB
```
    ARGB pixel format. This is the same as PF_XRGB, except that when decompressing, the X component is guaranteed to be equal to the maximum sample value, which can be interpreted as an opaque alpha channel.
    
    See Also:
    
    Constant Field Values
  - PF_CMYK
```
public static final int PF_CMYK
```
    CMYK pixel format. Unlike RGB, which is an additive color model used primarily for display, CMYK (Cyan/Magenta/Yellow/Key) is a subtractive color model used primarily for printing. In the CMYK color model, the value of each color component typically corresponds to an 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 packed-pixel CMYK images into YCCK JPEG images (see CS_YCCK) and decompressing YCCK JPEG images into packed-pixel CMYK images.
    
    See Also:
    
    Constant Field Values
  - NUMCS
```
public static final int NUMCS
```
    The number of JPEG colorspaces
    
    See Also:
    
    Constant Field Values
  - CS_RGB
```
public static final int CS_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 compressed from and decompressed to packed-pixel images with any of the extended RGB or grayscale pixel formats, but they cannot be compressed from or decompressed to planar YUV images.
    
    See Also:
    
    Constant Field Values
  - CS_YCbCr
```
public static final int CS_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 network or disk usage. YCbCr is the most common JPEG colorspace, and YCbCr JPEG images can be compressed from and decompressed to packed-pixel images with any of the extended RGB or grayscale pixel formats. YCbCr JPEG images can also be compressed from and decompressed to planar YUV images.
    
    See Also:
    
    Constant Field Values
  - CS_GRAY
```
public static final int CS_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 packed-pixel images with any of the extended RGB or grayscale pixel formats, or they can be compressed from and decompressed to planar YUV images.
    
    See Also:
    
    Constant Field Values
  - CS_CMYK
```
public static final int CS_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 compressed from and decompressed to packed-pixel images with the CMYK pixel format.
    
    See Also:
    
    Constant Field Values
  - CS_YCCK
```
public static final int CS_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 packed-pixel images with the CMYK pixel format.
    
    See Also:
    
    Constant Field Values
  - PARAM_STOPONWARNING
```
public static final int PARAM_STOPONWARNING
```
    Error handling behavior
    Value
    
    0 [default] Allow the current compression/decompression/transform operation to complete unless a fatal error is encountered.
    1 Immediately discontinue the current compression/decompression/transform operation if a warning (non-fatal error) occurs.
    See Also:
    
    Constant Field Values
  - PARAM_BOTTOMUP
```
public static final int PARAM_BOTTOMUP
```
    Row order in packed-pixel source/destination images
    Value
    
    0 [default] top-down (X11) order
    1 bottom-up (Windows, OpenGL) order
    See Also:
    
    Constant Field Values
  - PARAM_QUALITY
```
public static final int PARAM_QUALITY
```
    Perceptual quality of lossy JPEG images [compression only]
    Value
    
    1-100 (1 = worst quality but best compression, 100 = best quality but worst compression) [no default; must be explicitly specified]
    See Also:
    
    Constant Field Values
  - PARAM_SUBSAMP
```
public static final int PARAM_SUBSAMP
```
    Chrominance subsampling level
    The JPEG or YUV image uses (decompression, decoding) or will use (lossy compression, encoding) the specified level of chrominance subsampling.
    When pixels are converted from RGB to YCbCr (see CS_YCbCr) or from CMYK to YCCK (see CS_YCCK) 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 to small changes in color.) This is called "chrominance subsampling".
    Value
    
    One of TJ.SAMP_* [no default; must be explicitly specified for lossy compression, encoding, and decoding]
    See Also:
    
    Constant Field Values
  - PARAM_JPEGWIDTH
```
public static final int PARAM_JPEGWIDTH
```
    JPEG width (in pixels) [decompression only, read-only]
    
    See Also:
    
    Constant Field Values
  - PARAM_JPEGHEIGHT
```
public static final int PARAM_JPEGHEIGHT
```
    JPEG height (in pixels) [decompression only, read-only]
    
    See Also:
    
    Constant Field Values
  - PARAM_PRECISION
```
public static final int PARAM_PRECISION
```
    JPEG data precision (bits per sample) [decompression only, read-only]
    The JPEG image uses the specified number of bits per sample.
    Value
    
    8, 12, or 16
    
    12-bit data precision implies PARAM_OPTIMIZE unless PARAM_ARITHMETIC is set.
    See Also:
    
    Constant Field Values
  - PARAM_COLORSPACE
```
public static final int PARAM_COLORSPACE
```
    JPEG colorspace
    The JPEG image uses (decompression) or will use (lossy compression) the specified colorspace.
    Value
    
    One of TJ.CS_* [default for lossy compression: automatically selected based on the subsampling level and pixel format]
    See Also:
    
    Constant Field Values
  - PARAM_FASTUPSAMPLE
```
public static final int PARAM_FASTUPSAMPLE
```
    Chrominance upsampling algorithm [lossy decompression only]
    Value
    
    0 [default] Use smooth upsampling when decompressing a JPEG image that was compressed using chrominance subsampling. This creates a smooth transition between neighboring chrominance components in order to reduce upsampling artifacts in the decompressed image.
    1 Use the fastest chrominance upsampling algorithm available, which may combine upsampling with color conversion.
    See Also:
    
    Constant Field Values
  - PARAM_FASTDCT
```
public static final int PARAM_FASTDCT
```
    DCT/IDCT algorithm [lossy compression and decompression]
    Value
    
    0 [default] Use the most accurate DCT/IDCT algorithm available.
    1 Use the fastest DCT/IDCT algorithm available.
    
    This parameter is provided mainly for backward compatibility with libjpeg, which historically implemented several different DCT/IDCT algorithms because of performance limitations with 1990s CPUs. In the libjpeg-turbo implementation of the TurboJPEG API:
    
    The "fast" and "accurate" DCT/IDCT algorithms perform similarly on modern x86/x86-64 CPUs that support AVX2 instructions.
    The "fast" algorithm is generally only about 5-15% faster than the "accurate" algorithm on other types of CPUs.
    The difference in accuracy between the "fast" and "accurate" algorithms is the most pronounced at JPEG quality levels above 90 and tends to be more pronounced with decompression than with compression.
    The "fast" algorithm degrades and is not fully accelerated for JPEG quality levels above 97, so it will be slower than the "accurate" algorithm.
    See Also:
    
    Constant Field Values
  - PARAM_OPTIMIZE
```
public static final int PARAM_OPTIMIZE
```
    Optimized baseline entropy coding [lossy compression only]
    Value
    
    0 [default] The JPEG image will use the default Huffman tables.
    1 Optimal Huffman tables will be computed for the JPEG image. For lossless transformation, this can also be specified using TJTransform.OPT_OPTIMIZE.
    
    Optimized baseline entropy coding will improve compression slightly (generally 5% or less), but it will reduce compression performance considerably.
    See Also:
    
    Constant Field Values
  - PARAM_PROGRESSIVE
```
public static final int PARAM_PROGRESSIVE
```
    Progressive entropy coding
    Value
    
    0 [default for compression, lossless transformation] The lossy JPEG image uses (decompression) or will use (compression, lossless transformation) baseline entropy coding.
    1 The lossy JPEG image uses (decompression) or will use (compression, lossless transformation) progressive entropy coding. For lossless transformation, this can also be specified using TJTransform.OPT_PROGRESSIVE.
    
    Progressive entropy coding will generally improve compression relative to baseline entropy coding, but it will reduce compression and decompression performance considerably. Can be combined with PARAM_ARITHMETIC. Implies PARAM_OPTIMIZE unless PARAM_ARITHMETIC is also set.
    See Also:
    
    Constant Field Values
  - PARAM_SCANLIMIT
```
public static final int PARAM_SCANLIMIT
```
    Progressive JPEG scan limit for lossy JPEG images [decompression, lossless transformation]
    Setting this parameter will cause the decompression and transform operations to throw an error if the number of scans in a progressive JPEG image exceeds the specified limit. The primary purpose of this is to allow security-critical applications to guard against an exploit of the progressive JPEG format described in this report.
    Value
    
    maximum number of progressive JPEG scans that the decompression and transform operations will process [default: 0 (no limit)]
    See Also:
    
    PARAM_PROGRESSIVE, Constant Field Values
  - PARAM_ARITHMETIC
```
public static final int PARAM_ARITHMETIC
```
    Arithmetic entropy coding
    Value
    
    0 [default for compression, lossless transformation] The lossy JPEG image uses (decompression) or will use (compression, lossless transformation) Huffman entropy coding.
    1 The lossy JPEG image uses (decompression) or will use (compression, lossless transformation) arithmetic entropy coding. For lossless transformation, this can also be specified using TJTransform.OPT_ARITHMETIC.
    
    Arithmetic entropy coding will generally improve compression relative to Huffman entropy coding, but it will reduce compression and decompression performance considerably. Can be combined with PARAM_PROGRESSIVE.
    See Also:
    
    Constant Field Values
  - PARAM_LOSSLESS
```
public static final int PARAM_LOSSLESS
```
    Lossless JPEG
    Value
    
    0 [default for compression] The JPEG image is (decompression) or will be (compression) lossy/DCT-based.
    1 The JPEG image is (decompression) or will be (compression) lossless/predictive.
    
    In most cases, compressing and decompressing lossless JPEG images is considerably slower than compressing and decompressing lossy JPEG images, and lossless JPEG images are much larger than lossy JPEG images. Thus, lossless JPEG images are typically used only for applications that require mathematically lossless compression. Also note that the following features are not available with lossless JPEG images:
    
    Colorspace conversion (lossless JPEG images always use CS_RGB, CS_GRAY, or CS_CMYK, depending on the pixel format of the source image)
    Chrominance subsampling (lossless JPEG images always use SAMP_444)
    JPEG quality selection
    DCT/IDCT algorithm selection
    Progressive entropy coding
    Arithmetic entropy coding
    Compression from/decompression to planar YUV images
    Decompression scaling
    Lossless transformation
    See Also:
    
    PARAM_LOSSLESSPSV, PARAM_LOSSLESSPT, Constant Field Values
  - PARAM_LOSSLESSPSV
```
public static final int PARAM_LOSSLESSPSV
```
    Lossless JPEG predictor selection value (PSV)
    Value
    
    1-7 [default for compression: 1]
    
    Lossless JPEG compression shares no algorithms with lossy JPEG compression. Instead, it uses differential pulse-code modulation (DPCM), an algorithm whereby each sample is encoded as the difference between the sample's value and a "predictor", which is based on the values of neighboring samples. If Ra is the sample immediately to the left of the current sample, Rb is the sample immediately above the current sample, and Rc is the sample diagonally to the left and above the current sample, then the relationship between the predictor selection value and the predictor is as follows:
    
    PSV Predictor
    
    1 Ra
    
    2 Rb
    
    3 Rc
    
    4 Ra + Rb – Rc
    
    5 Ra + (Rb – Rc) / 2
    
    6 Rb + (Ra – Rc) / 2
    
    7 (Ra + Rb) / 2
    
    Predictors 1-3 are 1-dimensional predictors, whereas Predictors 4-7 are 2-dimensional predictors. The best predictor for a particular image depends on the image.
    See Also:
    
    PARAM_LOSSLESS, Constant Field Values
  - PARAM_LOSSLESSPT
```
public static final int PARAM_LOSSLESSPT
```
    Lossless JPEG point transform (Pt)
    Value
    
    0 through precision - 1, where precision is the JPEG data precision in bits [default for compression: 0]
    
    A point transform value of 0 is necessary in order to generate 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.)
    See Also:
    
    PARAM_LOSSLESS, PARAM_PRECISION, Constant Field Values
  - PARAM_RESTARTBLOCKS
```
public static final int PARAM_RESTARTBLOCKS
```
    JPEG restart marker interval in MCU blocks (lossy) or samples (lossless) [compression only]
    The nature of entropy coding is such that a corrupt JPEG image cannot be decompressed beyond the point of corruption unless it contains restart markers. A restart marker stops and restarts the entropy coding algorithm so that, if a JPEG image is corrupted, decompression can resume at the next marker. Thus, adding more restart markers improves the fault tolerance of the JPEG image, but adding too many restart markers can adversely affect the compression ratio and performance.
    Value
    
    the number of MCU blocks or samples between each restart marker [default: 0 (no restart markers)]
    
    Setting this parameter to a non-zero value sets PARAM_RESTARTROWS to 0.
    See Also:
    
    Constant Field Values
  - PARAM_RESTARTROWS
```
public static final int PARAM_RESTARTROWS
```
    JPEG restart marker interval in MCU rows (lossy) or sample rows (lossless) [compression only]
    See PARAM_RESTARTBLOCKS for a description of restart markers.
    Value
    
    the number of MCU rows or sample rows between each restart marker [default: 0 (no restart markers)]
    
    Setting this parameter to a non-zero value sets PARAM_RESTARTBLOCKS to 0.
    See Also:
    
    Constant Field Values
  - PARAM_XDENSITY
```
public static final int PARAM_XDENSITY
```
    JPEG horizontal pixel density
    Value
    
    The JPEG image has (decompression) or will have (compression) the specified horizontal pixel density [default for compression: 1].
    
    This value is stored in or read from the JPEG header. It does not affect the contents of the JPEG image.
    See Also:
    
    PARAM_DENSITYUNITS, Constant Field Values
  - PARAM_YDENSITY
```
public static final int PARAM_YDENSITY
```
    JPEG vertical pixel density
    Value
    
    The JPEG image has (decompression) or will have (compression) the specified vertical pixel density [default for compression: 1].
    
    This value is stored in or read from the JPEG header. It does not affect the contents of the JPEG image.
    See Also:
    
    PARAM_DENSITYUNITS, Constant Field Values
  - PARAM_DENSITYUNITS
```
public static final int PARAM_DENSITYUNITS
```
    JPEG pixel density units
    Value
    
    0 [default for compression] The pixel density of the JPEG image is expressed (decompression) or will be expressed (compression) in unknown units.
    1 The pixel density of the JPEG image is expressed (decompression) or will be expressed (compression) in units of pixels/inch.
    2 The pixel density of the JPEG image is expressed (decompression) or will be expressed (compression) in units of pixels/cm.
    
    This value is stored in or read from the JPEG header. It does not affect the contents of the JPEG image.
    See Also:
    
    PARAM_XDENSITY, PARAM_YDENSITY, Constant Field Values
  - PARAM_MAXMEMORY
```
public static final int PARAM_MAXMEMORY
```
    Memory limit for intermediate buffers
    Value
    
    the maximum amount of memory (in megabytes) that will be allocated for intermediate buffers, which are used with progressive JPEG compression and decompression, optimized baseline entropy coding, lossless JPEG compression, and lossless transformation [default: 0 (no limit)]
    See Also:
    
    Constant Field Values
  - PARAM_MAXPIXELS
```
public static final int PARAM_MAXPIXELS
```
    Image size limit [decompression, lossless transformation]
    Setting this parameter will cause the decompression and transform operations to throw an error if the number of pixels in the JPEG source image exceeds the specified limit. This allows security-critical applications to guard against excessive memory consumption.
    Value
    
    maximum number of pixels that the decompression and transform operations will process [default: 0 (no limit)]
    See Also:
    
    Constant Field Values
  - FLAG_BOTTOMUP
```
@Deprecated
public static final int FLAG_BOTTOMUP
```
    Deprecated.
    Use PARAM_BOTTOMUP instead.
    
    See Also:
    
    Constant Field Values
  - FLAG_FASTUPSAMPLE
```
@Deprecated
public static final int FLAG_FASTUPSAMPLE
```
    Deprecated.
    Use PARAM_FASTUPSAMPLE instead.
    
    See Also:
    
    Constant Field Values
  - FLAG_FASTDCT
```
@Deprecated
public static final int FLAG_FASTDCT
```
    Deprecated.
    Use PARAM_FASTDCT instead.
    
    See Also:
    
    Constant Field Values
  - FLAG_ACCURATEDCT
```
@Deprecated
public static final int FLAG_ACCURATEDCT
```
    Deprecated.
    Use PARAM_FASTDCT instead.
    
    See Also:
    
    Constant Field Values
  - FLAG_STOPONWARNING
```
@Deprecated
public static final int FLAG_STOPONWARNING
```
    Deprecated.
    Use PARAM_STOPONWARNING instead.
    
    See Also:
    
    Constant Field Values
  - FLAG_PROGRESSIVE
```
@Deprecated
public static final int FLAG_PROGRESSIVE
```
    Deprecated.
    Use PARAM_PROGRESSIVE instead.
    
    See Also:
    
    Constant Field Values
  - FLAG_LIMITSCANS
```
@Deprecated
public static final int FLAG_LIMITSCANS
```
    Deprecated.
    Use PARAM_SCANLIMIT instead.
    
    See Also:
    
    Constant Field Values
  - NUMERR
```
public static final int NUMERR
```
    The number of error codes
    
    See Also:
    
    Constant Field Values
  - ERR_WARNING
```
public static final int ERR_WARNING
```
    The error was non-fatal and recoverable, but the destination image may still be corrupt.
    NOTE: due to the design of the TurboJPEG Java API, only certain methods (specifically, TJDecompressor.decompress*() methods with a void return type) will complete and leave the destination image in a fully recoverable state after a non-fatal error occurs.
    
    See Also:
    
    Constant Field Values
  - ERR_FATAL
```
public static final int ERR_FATAL
```
    The error was fatal and non-recoverable.
    
    See Also:
    
    Constant Field Values
  - UNSCALED
```
public static final TJScalingFactor UNSCALED
```
    A TJScalingFactor instance that specifies a scaling factor of 1/1 (no scaling)
  - UNCROPPED
```
public static final java.awt.Rectangle UNCROPPED
```
    A java.awt.Rectangle instance that specifies no cropping
- Method Detail
  - getMCUWidth
```
public static int getMCUWidth(int subsamp)
```
    Returns the MCU block width for the given level of chrominance subsampling.
    
    Parameters:
    
    subsamp - the level of chrominance subsampling (one of SAMP_*)
    
    Returns:
    
    the MCU block width for the given level of chrominance subsampling.
  - getMCUHeight
```
public static int getMCUHeight(int subsamp)
```
    Returns the MCU block height for the given level of chrominance subsampling.
    
    Parameters:
    
    subsamp - the level of chrominance subsampling (one of SAMP_*)
    
    Returns:
    
    the MCU block height for the given level of chrominance subsampling.
  - getPixelSize
```
public static int getPixelSize(int pixelFormat)
```
    Returns the pixel size (in samples) for the given pixel format.
    
    Parameters:
    
    pixelFormat - the pixel format (one of PF_*)
    
    Returns:
    
    the pixel size (in samples) for the given pixel format.
  - getRedOffset
```
public static int getRedOffset(int pixelFormat)
```
    For the given pixel format, returns the number of samples that the red component is offset from the start of the pixel. For instance, if an 8-bit-per-sample pixel of format TJ.PF_BGRX is stored in char pixel[], then the red component will be pixel[TJ.getRedOffset(TJ.PF_BGRX)].
    
    Parameters:
    
    pixelFormat - the pixel format (one of PF_*)
    
    Returns:
    
    the red offset for the given pixel format, or -1 if the pixel format does not have a red component.
  - getGreenOffset
```
public static int getGreenOffset(int pixelFormat)
```
    For the given pixel format, returns the number of samples that the green component is offset from the start of the pixel. For instance, if an 8-bit-per-sample pixel of format TJ.PF_BGRX is stored in char pixel[], then the green component will be pixel[TJ.getGreenOffset(TJ.PF_BGRX)].
    
    Parameters:
    
    pixelFormat - the pixel format (one of PF_*)
    
    Returns:
    
    the green offset for the given pixel format, or -1 if the pixel format does not have a green component.
  - getBlueOffset
```
public static int getBlueOffset(int pixelFormat)
```
    For the given pixel format, returns the number of samples that the blue component is offset from the start of the pixel. For instance, if an 8-bit-per-sample pixel of format TJ.PF_BGRX is stored in char pixel[], then the blue component will be pixel[TJ.getBlueOffset(TJ.PF_BGRX)].
    
    Parameters:
    
    pixelFormat - the pixel format (one of PF_*)
    
    Returns:
    
    the blue offset for the given pixel format, or -1 if the pixel format does not have a blue component.
  - getAlphaOffset
```
public static int getAlphaOffset(int pixelFormat)
```
    For the given pixel format, returns the number of samples that the alpha component is offset from the start of the pixel. For instance, if an 8-bit-per-sample pixel of format TJ.PF_BGRA is stored in char pixel[], then the alpha component will be pixel[TJ.getAlphaOffset(TJ.PF_BGRA)].
    
    Parameters:
    
    pixelFormat - the pixel format (one of PF_*)
    
    Returns:
    
    the alpha offset for the given pixel format, or -1 if the pixel format does not have a alpha component.
  - bufSize
```
public static int bufSize(int width,
                          int height,
                          int jpegSubsamp)
```
    Returns the maximum size of the buffer (in bytes) required to hold a JPEG image with the given width, height, and level of chrominance subsampling.
    
    Parameters:
    
    width - the width (in pixels) of the JPEG image
    
    height - the height (in pixels) of the JPEG image
    
    jpegSubsamp - the level of chrominance subsampling to be used when generating the JPEG image (one of TJ.SAMP_*.) SAMP_UNKNOWN is treated like SAMP_444, since a buffer large enough to hold a JPEG image with no subsampling should also be large enough to hold a JPEG image with an arbitrary level of subsampling. Note that lossless JPEG images always use SAMP_444.
    
    Returns:
    
    the maximum size of the buffer (in bytes) required to hold a JPEG image with the given width, height, and level of chrominance subsampling.
  - bufSizeYUV
```
public static int bufSizeYUV(int width,
                             int align,
                             int height,
                             int subsamp)
```
    Returns the size of the buffer (in bytes) required to hold a unified planar YUV image with the given width, height, and level of chrominance subsampling.
    
    Parameters:
    
    width - the width (in pixels) of the YUV image
    
    align - row alignment (in bytes) of the YUV image (must be a power of 2.) Setting this parameter to n specifies that each row in each plane of the YUV image will be padded to the nearest multiple of n bytes (1 = unpadded.)
    
    height - the height (in pixels) of the YUV image
    
    subsamp - the level of chrominance subsampling used in the YUV image (one of TJ.SAMP_*)
    
    Returns:
    
    the size of the buffer (in bytes) required to hold a unified planar YUV image with the given width, height, and level of chrominance subsampling.
  - planeSizeYUV
```
public static int planeSizeYUV(int componentID,
                               int width,
                               int stride,
                               int height,
                               int subsamp)
```
    Returns the size of the buffer (in bytes) required to hold a YUV image plane with the given parameters.
    
    Parameters:
    
    componentID - ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
    
    width - width (in pixels) of the YUV image. NOTE: this is the width of the whole image, not the plane width.
    
    stride - bytes per row in the image plane.
    
    height - height (in pixels) of the YUV image. NOTE: this is the height of the whole image, not the plane height.
    
    subsamp - the level of chrominance subsampling used in the YUV image (one of TJ.SAMP_*)
    
    Returns:
    
    the size of the buffer (in bytes) required to hold a YUV image plane with the given parameters.
  - planeWidth
```
public static int planeWidth(int componentID,
                             int width,
                             int subsamp)
```
    Returns the plane width of a YUV image plane with the given parameters. Refer to YUVImage for a description of plane width.
    
    Parameters:
    
    componentID - ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
    
    width - width (in pixels) of the YUV image
    
    subsamp - the level of chrominance subsampling used in the YUV image (one of TJ.SAMP_*)
    
    Returns:
    
    the plane width of a YUV image plane with the given parameters.
  - planeHeight
```
public static int planeHeight(int componentID,
                              int height,
                              int subsamp)
```
    Returns the plane height of a YUV image plane with the given parameters. Refer to YUVImage for a description of plane height.
    
    Parameters:
    
    componentID - ID number of the image plane (0 = Y, 1 = U/Cb, 2 = V/Cr)
    
    height - height (in pixels) of the YUV image
    
    subsamp - the level of chrominance subsampling used in the YUV image (one of TJ.SAMP_*)
    
    Returns:
    
    the plane height of a YUV image plane with the given parameters.
  - getScalingFactors
```
public static TJScalingFactor[] getScalingFactors()
```
    Returns a list of fractional scaling factors that the JPEG decompressor supports.
    
    Returns:
    
    a list of fractional scaling factors that the JPEG decompressor supports.

PSV	Predictor
1	Ra
2	Rb
3	Rc
4	Ra + Rb – Rc
5	Ra + (Rb – Rc) / 2
6	Rb + (Ra – Rc) / 2
7	(Ra + Rb) / 2

Class TJ

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

NUMSAMP

SAMP_444

SAMP_422

SAMP_420

SAMP_GRAY

SAMP_440

SAMP_411

SAMP_441

SAMP_UNKNOWN

NUMPF

PF_RGB

PF_BGR

PF_RGBX

PF_BGRX

PF_XBGR

PF_XRGB

PF_GRAY

PF_RGBA

PF_BGRA

PF_ABGR

PF_ARGB

PF_CMYK

NUMCS

CS_RGB

CS_YCbCr

CS_GRAY

CS_CMYK

CS_YCCK

PARAM_STOPONWARNING

PARAM_BOTTOMUP

PARAM_QUALITY

PARAM_SUBSAMP

PARAM_JPEGWIDTH

PARAM_JPEGHEIGHT

PARAM_PRECISION

PARAM_COLORSPACE

PARAM_FASTUPSAMPLE

PARAM_FASTDCT

PARAM_OPTIMIZE

PARAM_PROGRESSIVE

PARAM_SCANLIMIT

PARAM_ARITHMETIC

PARAM_LOSSLESS

PARAM_LOSSLESSPSV

PARAM_LOSSLESSPT

PARAM_RESTARTBLOCKS

PARAM_RESTARTROWS

PARAM_XDENSITY

PARAM_YDENSITY

PARAM_DENSITYUNITS

PARAM_MAXMEMORY

PARAM_MAXPIXELS

FLAG_BOTTOMUP

FLAG_FASTUPSAMPLE

FLAG_FASTDCT

FLAG_ACCURATEDCT

FLAG_STOPONWARNING

FLAG_PROGRESSIVE

FLAG_LIMITSCANS

NUMERR

ERR_WARNING

ERR_FATAL

UNSCALED

UNCROPPED

Method Detail

getMCUWidth

getMCUHeight

getPixelSize

getRedOffset

getGreenOffset

getBlueOffset

getAlphaOffset

bufSize

bufSizeYUV

planeSizeYUV