author | Claus Gittinger <cg@exept.de> |
Thu, 10 Apr 2003 16:26:11 +0200 | |
changeset 1745 | 4fa0fad2a463 |
parent 1694 | 3a77d9b69cf7 |
child 1759 | f52382e5a9b8 |
permissions | -rw-r--r-- |
308 | 1 |
" |
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COPYRIGHT (c) 1996 by Claus Gittinger |
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All Rights Reserved |
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This software is furnished under a license and may be used |
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only in accordance with the terms of that license and with the |
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inclusion of the above copyright notice. This software may not |
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be provided or otherwise made available to, or used by, any |
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other person. No title to or ownership of the software is |
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hereby transferred. |
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" |
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1671 | 15 |
"{ Package: 'stx:libview2' }" |
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308 | 17 |
ImageReader subclass:#PNGReader |
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instanceVariableNames:'colorType depth compressionMethod filterMethod interlaceMode |
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redBytes greenBytes blueBytes' |
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classVariableNames:'' |
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poolDictionaries:'' |
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1745
4fa0fad2a463
code cleanup (colorMap handling)
Claus Gittinger <cg@exept.de>
parents:
1694
diff
changeset
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category:'Graphics-Images-Readers' |
308 | 23 |
! |
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398 | 25 |
!PNGReader class methodsFor:'documentation'! |
308 | 26 |
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copyright |
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" |
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COPYRIGHT (c) 1996 by Claus Gittinger |
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All Rights Reserved |
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This software is furnished under a license and may be used |
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only in accordance with the terms of that license and with the |
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inclusion of the above copyright notice. This software may not |
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be provided or otherwise made available to, or used by, any |
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other person. No title to or ownership of the software is |
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hereby transferred. |
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" |
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! |
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documentation |
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" |
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This class will provide methods for loading PNG pictures. |
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It is currenty unfinished and untested (need a Zlib inflater). |
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In the meantime, use a pngtoXXX converter. |
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308 | 48 |
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[See also:] |
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Image Form Icon |
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BlitImageReader FaceReader GIFReader JPEGReader PBMReader PCXReader |
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ST80FormReader SunRasterReader TargaReader TIFFReader WindowsIconReader |
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XBMReader XPMReader XWDReader |
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[author:] |
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Claus Gittinger |
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" |
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1694 | 58 |
! |
308 | 59 |
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1694 | 60 |
examples |
61 |
" |
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PNGReader fromFile:'/home/cg/AudioExplorer_51_files/use_small.png' |
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" |
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308 | 64 |
! ! |
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398 | 66 |
!PNGReader class methodsFor:'initialization'! |
308 | 67 |
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initialize |
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"install myself in the Image classes fileFormat table |
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398 | 70 |
for the `.png' extension." |
308 | 71 |
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647 | 72 |
"/ not yet finished - do not add |
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"/ MIMETypes defineImageType:'image/x-png' suffix:'png' reader:self. |
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308 | 74 |
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398 | 75 |
"Modified: 1.2.1997 / 15:02:47 / cg" |
308 | 76 |
! ! |
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398 | 78 |
!PNGReader class methodsFor:'testing'! |
308 | 79 |
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isValidImageFile:aFileName |
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"return true, if aFileName contains a PNG image" |
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|inStream magic| |
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inStream := self streamReadingFile:aFileName. |
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inStream isNil ifTrue:[^ false]. |
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inStream binary. |
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magic := ByteArray new:8. |
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inStream nextBytes:8 into:magic. |
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inStream close. |
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^ (magic = #[137 80 78 71 13 10 26 10]) |
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" |
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self isValidImageFile:'/home/cg/AudioExplorer_51_files/use_small.png' |
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" |
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308 | 100 |
"Modified: 21.6.1996 / 20:38:46 / cg" |
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! ! |
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!PNGReader methodsFor:'private'! |
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getChunk |
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|len type crc| |
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inStream atEnd ifTrue:[^ false]. |
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len := inStream nextLongMSB:true. |
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type := String new:4. |
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(inStream nextBytes:4 into:type) ~~ 4 ifTrue:[^ false]. |
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"/ 'len: ' print. len print. ' type: ' print. type printCR. |
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type = 'IEND' ifTrue:[^ false]. |
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(self processChunk:type len:len) ifFalse:[^ false]. |
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crc := inStream nextLongMSB:true. "/ ignored - for now |
308 | 121 |
^ true |
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"Created: 21.6.1996 / 21:09:36 / cg" |
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"Modified: 21.6.1996 / 21:20:26 / cg" |
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! |
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getIHDRChunk |
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|len type crc| |
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len := inStream nextLongMSB:true. |
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type := String new:4. |
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inStream nextBytes:4 into:type. |
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type = 'IHDR' ifFalse:[self halt. ^ false]. |
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len == 13 ifFalse:[self halt. ^ false]. |
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width := inStream nextLongMSB:true. |
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height := inStream nextLongMSB:true. |
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(width <= 0 or:[height <= 0]) ifTrue:[ |
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'PNGReader: invalid dimension(s)' infoPrintCR. |
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^ false. |
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]. |
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depth := inStream nextByte. |
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colorType := inStream nextByte. |
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compressionMethod := inStream nextByte. |
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filterMethod := inStream nextByte. |
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interlaceMode := inStream nextByte. |
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inStream skip:4. |
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"/ crc := inStream nextLongMSB:true. |
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^ true |
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"Modified: 21.6.1996 / 21:38:35 / cg" |
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! |
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159 |
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processBKGDChunkLen:len |
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inStream skip:len. |
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^ true |
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"Created: 21.6.1996 / 21:15:49 / cg" |
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! |
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processChunk:type len:len |
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type = 'gAMA' ifTrue:[^ self processGAMAChunkLen:len]. |
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type = 'sBIT' ifTrue:[^ self processSBITChunkLen:len]. |
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type = 'tEXt' ifTrue:[^ self processTEXTChunkLen:len]. |
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type = 'IDAT' ifTrue:[^ self processIDATChunkLen:len]. |
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type = 'tIME' ifTrue:[^ self processTIMEChunkLen:len]. |
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type = 'bKGD' ifTrue:[^ self processBKGDChunkLen:len]. |
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type = 'zTXt' ifTrue:[^ self processZTXTChunkLen:len]. |
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type = 'PLTE' ifTrue:[^ self processPLTEChunkLen:len]. |
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type = 'pHYs' ifTrue:[^ self processPHYSChunkLen:len]. |
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type = 'tRNS' ifTrue:[^ self processTRNSChunkLen:len]. |
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type = 'IHDR' ifTrue:[^ self processIHDRChunkLen:len]. |
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308 | 181 |
('PNGReader: unrecognized chunk: ' , type , ' ignored.') infoPrintCR. |
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inStream skip:len. |
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^ true. |
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"Created: 21.6.1996 / 21:10:37 / cg" |
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"Modified: 21.6.1996 / 21:22:37 / cg" |
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! |
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processGAMAChunkLen:len |
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inStream skip:len. |
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^ true |
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"Created: 21.6.1996 / 21:10:52 / cg" |
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! |
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processIDATChunkLen:len |
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interlaceMode == 0 ifTrue: [ |
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^ self processNonInterlacedDATA:len |
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]. |
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^ self processInterlacedDATA:len |
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! |
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processIHDRChunkLen:len |
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"header chunk - currently unhandled" |
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|width height bitsPerChannel interlaceMethod palette image bitsPerPixel bytesPerScanline rowSize| |
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self halt. |
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width := inStream nextLongMSB:true. "/ 1..4 |
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height := inStream nextLongMSB:true. "/ 5..8 |
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bitsPerChannel := inStream nextByte. "/ 9 |
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colorType := inStream nextByte. "/ 10 |
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inStream nextByte. "/ 11 |
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inStream nextByte. "/ 12 |
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interlaceMethod := inStream nextByte. "/ 13 |
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(#(2 4 6) includes: colorType) ifTrue:[ |
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depth := 32. |
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palette := self class defaultPalette. |
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image := Image extent: width @ height depth: depth palette: palette |
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]. |
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(#(0 3) includes: colorType) ifTrue:[ |
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depth := bitsPerChannel min: 8. |
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image := Image extent: width @ height |
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depth: depth |
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palette: (colorType = 0 |
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ifTrue: [self grayColorsFor: depth] |
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ifFalse: [palette := self class defaultPalette])]. |
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bitsPerPixel := (BPP at: colorType + 1) at: bitsPerChannel highBit. |
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bytesPerScanline := (width * bitsPerPixel + 7) // 8. |
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rowSize := image width * image depth + 31 >> 5 |
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! |
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processInterlacedDATA:len |
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inStream skip:len. |
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^ true |
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! |
308 | 239 |
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processNonInterlacedDATA:len |
241 |
| zlibReader filter temp prevScanline thisScanline bytesPerScanline filtersSeen| |
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1694 | 243 |
zlibReader := ZLibReadStream on:inStream from: 1 to:len. |
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prevScanline := ByteArray new: bytesPerScanline. |
245 |
thisScanline := ByteArray new: bytesPerScanline. |
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0 to: height - 1 do: |
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[:index | |
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filter := (zlibReader next: 1) first. |
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filtersSeen add: filter. |
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(filter isNil or: [(filter between: 0 and: 4) not]) ifTrue: [^self]. |
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thisScanline := zlibReader next: bytesPerScanline into: thisScanline startingAt: 1. |
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self filterScanline: filter count: bytesPerScanline. |
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self copyPixels: index. |
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temp := prevScanline. |
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prevScanline := thisScanline. |
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thisScanline := temp] |
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! |
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processPHYSChunkLen:len |
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"physical pixel chunk - currently unhandled" |
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'PNGReader: unhandled chunk type: PHYS' infoPrintCR. |
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^ false |
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308 | 264 |
! |
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processPLTEChunkLen:len |
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"read a color palette" |
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308 | 269 |
|n "{ Class: SmallInteger }"| |
270 |
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(len \\ 3) ~~ 0 ifTrue:[ |
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'PNGReader: invalid size of PLTE chunk' infoPrintCR. |
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^ false |
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]. |
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n := len // 3. |
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redBytes := ByteArray new:n. |
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greenBytes := ByteArray new:n. |
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blueBytes := ByteArray new:n. |
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1 to:n do:[:i | |
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redBytes at:i put:(inStream nextByte). |
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greenBytes at:i put:(inStream nextByte). |
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blueBytes at:i put:(inStream nextByte) |
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]. |
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^ true |
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"Created: 21.6.1996 / 21:22:28 / cg" |
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"Modified: 21.6.1996 / 21:43:01 / cg" |
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! |
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processSBITChunkLen:len |
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inStream skip:len. |
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^ true |
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"Created: 21.6.1996 / 21:13:09 / cg" |
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! |
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298 |
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processTEXTChunkLen:len |
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inStream skip:len. |
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^ true |
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"Modified: 21.6.1996 / 21:15:27 / cg" |
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! |
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305 |
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processTIMEChunkLen:len |
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inStream skip:len. |
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^ true |
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"Created: 21.6.1996 / 21:15:43 / cg" |
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"Modified: 21.6.1996 / 21:20:42 / cg" |
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! |
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processZTXTChunkLen:len |
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inStream skip:len. |
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^ true |
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"Created: 21.6.1996 / 21:15:58 / cg" |
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! ! |
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!PNGReader methodsFor:'reading from file'! |
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fromStream:aStream |
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"read a stream containing a PNG image. |
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Leave image description in instance variables." |
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|header| |
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inStream := aStream. |
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aStream binary. |
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1671 | 332 |
"PNG-files are always msb (network-world)" |
308 | 333 |
byteOrder := #msb. |
334 |
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header := ByteArray new:8. |
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aStream nextBytes:8 into:header. |
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header ~= #[137 80 78 71 13 10 26 10] ifTrue:[ |
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'PNGReader: not a png file.' infoPrintCR. |
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^ nil |
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]. |
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(self getIHDRChunk) ifFalse:[ |
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'PNGReader: required IHDR chunk missing.' infoPrintCR. |
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^ nil |
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]. |
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compressionMethod ~~ 0 ifTrue:[ |
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('PNGReader: compressionMethod ' , compressionMethod printString , ' not supported.') infoPrintCR. |
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^ nil |
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]. |
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351 |
filterMethod > 0 ifTrue:[ |
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'PNGReader: invalid filterMethod' infoPrintCR. |
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^ nil. |
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]. |
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interlaceMode > 1 ifTrue:[ |
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356 |
'PNGReader: invalid interlaceMode' infoPrintCR. |
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^ nil. |
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]. |
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1671 | 359 |
(self setColorType:colorType) ifFalse:[ |
308 | 360 |
^ nil |
1671 | 361 |
]. |
308 | 362 |
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1671 | 363 |
[self getChunk] whileTrue. |
308 | 364 |
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365 |
photometric == #palette ifTrue:[ |
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366 |
redBytes isNil ifTrue:[ |
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367 |
'PNGReader: missing palette chunk.' infoPrintCR. |
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368 |
^ nil |
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]. |
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370 |
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371 |
colorMap := Colormap |
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372 |
redVector:redBytes |
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373 |
greenVector:greenBytes |
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374 |
blueVector:blueBytes. |
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]. |
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376 |
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377 |
self halt. |
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378 |
" |
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379 |
PNGReader fromFile:'/home/cg/libpng-0.89c/pngtest.png' |
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380 |
" |
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381 |
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382 |
"Modified: 21.6.1996 / 21:44:34 / cg" |
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1671 | 383 |
! |
384 |
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385 |
setColorType:colorType |
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386 |
colorType == 0 ifTrue:[ |
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387 |
photometric := #blackIs0. |
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388 |
samplesPerPixel := 1. |
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389 |
bitsPerSample := Array with:depth. |
|
390 |
^ true. |
|
391 |
]. |
|
392 |
||
393 |
colorType == 2 ifTrue:[ |
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394 |
depth < 8 ifTrue:[ |
|
395 |
'PNGReader: invalid colorType/depth combination' infoPrintCR. |
|
396 |
^ false. |
|
397 |
]. |
|
398 |
photometric := #rgb. |
|
399 |
samplesPerPixel := 3. |
|
400 |
bitsPerSample := Array with:depth with:depth with:depth. |
|
401 |
^ true. |
|
402 |
]. |
|
403 |
||
404 |
colorType == 3 ifTrue:[ |
|
405 |
depth == 16 ifTrue:[ |
|
406 |
'PNGReader: invalid colorType/depth combination' infoPrintCR. |
|
407 |
^ false. |
|
408 |
]. |
|
409 |
photometric := #palette. |
|
410 |
samplesPerPixel := 1. |
|
411 |
bitsPerSample := Array with:depth. |
|
412 |
^ true. |
|
413 |
]. |
|
414 |
||
415 |
colorType == 4 ifTrue:[ |
|
416 |
depth < 8 ifTrue:[ |
|
417 |
'PNGReader: invalid colorType/depth combination' infoPrintCR. |
|
418 |
^ false. |
|
419 |
]. |
|
420 |
photometric := #blackIs0. |
|
421 |
samplesPerPixel := 2. |
|
422 |
bitsPerSample := Array with:depth with:depth. |
|
423 |
^ true. |
|
424 |
]. |
|
425 |
||
426 |
colorType == 6 ifTrue:[ |
|
427 |
depth < 8 ifTrue:[ |
|
428 |
'PNGReader: invalid colorType/depth combination' infoPrintCR. |
|
429 |
^ false. |
|
430 |
]. |
|
431 |
photometric := #rgb. |
|
432 |
samplesPerPixel := 4. |
|
433 |
bitsPerSample := Array with:depth with:depth with:depth with:depth. |
|
434 |
^ true. |
|
435 |
]. |
|
436 |
||
437 |
('PNGReader: invalid colorType: ' , colorType printString , '.') infoPrintCR. |
|
438 |
^ false |
|
308 | 439 |
! ! |
440 |
||
398 | 441 |
!PNGReader class methodsFor:'documentation'! |
308 | 442 |
|
443 |
version |
|
1745
4fa0fad2a463
code cleanup (colorMap handling)
Claus Gittinger <cg@exept.de>
parents:
1694
diff
changeset
|
444 |
^ '$Header: /cvs/stx/stx/libview2/PNGReader.st,v 1.6 2003-04-10 14:25:36 cg Exp $' |
308 | 445 |
! ! |
1671 | 446 |
|
308 | 447 |
PNGReader initialize! |