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JPEGReadWriter
  category: Graphics-Files
  superclass: ImageReadWriter
  subclasses: FlashJPEGDecoder

I am a subclass of ImageReadWriter that understands JFIF file streams, and can decode JPEG images.
This code is based upon the Independent Joint Photographic Experts Group (IJPEG) software, originally written in C by Tom Lane, Philip Gladstone, Luis Ortiz, Jim Boucher, Lee Crocker, Julian Minguillon, George Phillips, Davide Rossi, Ge' Weijers, and other members of the Independent JPEG Group.

instance methods
  accessing
  hACTable
hDCTable
qTable

  colorspace conversion
  colorConvertFloatYCbCrMCU
colorConvertGrayscaleMCU
colorConvertIntYCbCrMCU
colorConvertMCU
primColorConvertGrayscaleMCU
primColorConvertGrayscaleMCU:bits:residuals:ditherMask:
primColorConvertIntYCbCrMCU
primColorConvertYCbCrMCU:bits:residuals:ditherMask:
sampleFloatRangeLimit:
sampleRangeLimit:

  dct
  dctFloatRangeLimit:
idctBlockFloat:component:
idctBlockInt:component:
idctBlockInt:qt:
idctMCU
primIdctBlockInt:component:
primIdctInt:qt:
scaleQuantizationTable:

  error handling
  notSupported:

  huffman encoding
  decodeBlockInto:component:dcTable:acTable:
decodeMCU
getBits:
primDecodeBlockInto:component:dcTable:acTable:stream:
processRestart
scaleAndSignExtend:inFieldWidth:

  marker parsing
  initialSOSSetup
okToIgnoreMarker:
parseAPPn
parseDecoderRestartInterval
parseFirstMarker
parseHuffmanTable
parseNOP
parseNextMarker
parseQuantizationTable
parseStartOfFile
parseStartOfInput
parseStartOfScan
perScanSetup
skipMarker

  preferences
  useFloatingPoint

  private
  on:

  public access
  decompressionTest
nextImage
nextImageDitheredToDepth:
setStream:

  testing
  understandsImageFormat

class methods
  initialization
  initialize

instance methods
  accessing top  
 

hACTable


 

hDCTable


 

qTable


  colorspace conversion top  
 

colorConvertFloatYCbCrMCU


 

colorConvertGrayscaleMCU


 

colorConvertIntYCbCrMCU


 

colorConvertMCU


 

primColorConvertGrayscaleMCU


 

primColorConvertGrayscaleMCU:bits:residuals:ditherMask:


 

primColorConvertIntYCbCrMCU


 

primColorConvertYCbCrMCU:bits:residuals:ditherMask:


 

sampleFloatRangeLimit:


 

sampleRangeLimit:


  dct top  
 

dctFloatRangeLimit:


 

idctBlockFloat:component:


 

idctBlockInt:component:


 

idctBlockInt:qt:


 

idctMCU


 

primIdctBlockInt:component:


 

primIdctInt:qt:


 

scaleQuantizationTable:


  error handling top  
 

notSupported:


  huffman encoding top  
 

decodeBlockInto:component:dcTable:acTable:


 

decodeMCU


 

getBits:


 

primDecodeBlockInto:component:dcTable:acTable:stream:


 

processRestart


 

scaleAndSignExtend:inFieldWidth:


  marker parsing top  
 

initialSOSSetup


 

okToIgnoreMarker:


 

parseAPPn


 

parseDecoderRestartInterval


 

parseFirstMarker


 

parseHuffmanTable


 

parseNOP

don't need to do anything, here


 

parseNextMarker

Parse the next marker of the stream


 

parseQuantizationTable


 

parseStartOfFile


 

parseStartOfInput


 

parseStartOfScan


 

perScanSetup


 

skipMarker


  preferences top  
 

useFloatingPoint


  private top  
 

on:


  public access top  
 

decompressionTest

Test decompression; don't generate actual image


 

nextImage

Dencoding an image on stream and answer the image.


 

nextImageDitheredToDepth:


 

setStream:

Feed it in from an existing source


  testing top  
 

understandsImageFormat

Answer true if the image stream format is understood by this decoder.


class methods
  initialization top  
 

initialize

JPEGReadWriter initialize