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JPEGColorComponent
  category: Graphics-Files
  superclass: Object
  subclasses:

I represent a single component of color in JPEG YCbCr color space. I can accept a list of blocks in my component from the current MCU, then stream the samples from this block for use in color conversion. I also store the running DC sample value for my component, used by the Huffman decoder.

The following layout is fixed for the JPEG primitives to work:
currentX <SmallInteger>
currentY <SmallInteger>
hSampleFactor <SmallInteger>
vSampleFactor <SmallInteger>
mcuBlocks <Array of: <IntegerArray of: DCTSize2 * Integer>>
widthInBlocks <SmallInteger>
heightInBlocks <SmallInteger>
dctSize <SmallInteger>
mcuWidth <SmallInteger>
mcuHeight <SmallInteger>
priorDCValue <SmallInteger>

instance methods
  accessing
  acTableIndex
acTableIndex:
dcTableIndex
dcTableIndex:
heightInBlocks
heightInBlocks:
id
id:
mcuWidth:mcuHeight:dctSize:
priorDCValue:
qTableIndex
qTableIndex:
totalMcuBlocks
updateDCValue:
widthInBlocks
widthInBlocks:

  sample streaming
  initializeSampleStreamBlocks:
nextSample
resetSampleStream

class methods
  no messages
 

instance methods
  accessing top  
 

acTableIndex


 

acTableIndex:


 

dcTableIndex


 

dcTableIndex:


 

heightInBlocks


 

heightInBlocks:


 

id


 

id:


 

mcuWidth:mcuHeight:dctSize:


 

priorDCValue:


 

qTableIndex


 

qTableIndex:


 

totalMcuBlocks


 

updateDCValue:


 

widthInBlocks


 

widthInBlocks:


  sample streaming top  
 

initializeSampleStreamBlocks:


 

nextSample


 

resetSampleStream


class methods
  no messages top