mirror of https://github.com/status-im/nimPNG.git
fix predefined filters
This commit is contained in:
andri lim
parent
7c55ff3f9d
commit
5f0dd589be
38
nimPNG.nim
38
nimPNG.nim
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@ -41,7 +41,7 @@ type
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LCT_GREY_ALPHA = 4, # greyscale with alpha: 8,16 bit
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LCT_RGBA = 6 # RGB with alpha: 8,16 bit
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PNGFilter0 = enum
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PNGFilter* = enum
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FLT_NONE,
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FLT_SUB,
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FLT_UP,
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@ -976,7 +976,7 @@ proc addColorBits(output: var DataBuf, index, bits, input: int) =
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if p == 0: output[idx] = chr(val)
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else: output[idx] = chr(ord(output[idx]) or val)
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proc unfilterScanLine(recon: var DataBuf, scanLine, precon: DataBuf, byteWidth, len: int, filterType: PNGFilter0) =
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proc unfilterScanLine(recon: var DataBuf, scanLine, precon: DataBuf, byteWidth, len: int, filterType: PNGFilter) =
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# For PNG filter method 0
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# unfilter a PNG image scanLine by scanLine. when the pixels are smaller than 1 byte,
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# the filter works byte per byte (byteWidth = 1)
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@ -1033,7 +1033,7 @@ proc unfilter(output: var DataBuf, input: DataBuf, w, h, bpp: int) =
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for y in 0..h-1:
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let outIndex = lineBytes * y
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let inIndex = (1 + lineBytes) * y # the extra filterbyte added to each row
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let filterType = PNGFilter0(input[inindex])
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let filterType = PNGFilter(input[inindex])
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let scanLine = input.subbuffer(inIndex + 1)
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var outp = output.subbuffer(outIndex)
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unfilterScanLine(outp, scanLine, prevLine, byteWidth, lineBytes, filterType)
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@ -2101,7 +2101,7 @@ type
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#used if filter_strategy is LFS_PREDEFINED. In that case, this must point to a buffer with
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#the same length as the amount of scanLines in the image, and each value must <= 5.
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#Don't forget that filter_palette_zero must be set to false to ensure this is also used on palette or low bitdepth images.
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predefinedFilters*: string
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predefinedFilters*: seq[PNGFilter]
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#force creating a PLTE chunk if colorType is 2 or 6 (= a suggested palette).
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#If colorType is 3, PLTE is _always_ created.
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@ -2153,7 +2153,7 @@ proc makePNGEncoder*(): PNGEncoder =
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s.modeIn = newColorMode()
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s.modeOut = newColorMode()
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s.forcePalette = false
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s.predefinedFilters = ""
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s.predefinedFilters = @[]
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s.addID = false
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s.textCompression = true
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s.interlaceMethod = IM_NONE
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@ -2675,7 +2675,7 @@ proc addPaddingBits(output: var DataBuf, input: DataBuf, olinebits, ilinebits, h
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setBitOfReversedStream(obp, output, bit)
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for x in 0..diff-1: setBitOfReversedStream(obp, output, 0)
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proc filterScanLine(output: var DataBuf, scanLine, prevLine: DataBuf, len, byteWidth: int, filterType: PNGFilter0) =
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proc filterScanLine(output: var DataBuf, scanLine, prevLine: DataBuf, len, byteWidth: int, filterType: PNGFilter) =
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case filterType
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of FLT_NONE:
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for i in 0..len-1: output[i] = scanLine[i]
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@ -2748,7 +2748,7 @@ proc filterMinsum(output: var DataBuf, input: DataBuf, w, h, bpp: int) =
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#try the 5 filter types
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for fType in 0..4:
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var outp = initBuffer(attempt[fType])
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filterScanLine(outp, input.subbuffer(y * lineBytes), prevLine, lineBytes, byteWidth, PNGFilter0(fType))
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filterScanLine(outp, input.subbuffer(y * lineBytes), prevLine, lineBytes, byteWidth, PNGFilter(fType))
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#calculate the sum of the result
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sum[fType] = 0
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if fType == 0:
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@ -2793,7 +2793,7 @@ proc filterEntropy(output: var DataBuf, input: DataBuf, w, h, bpp: int) =
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#try the 5 filter types
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for fType in 0..4:
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var outp = initBuffer(attempt[fType])
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filterScanLine(outp, input.subbuffer(y * lineBytes), prevLine, lineBytes, byteWidth, PNGFilter0(fType))
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filterScanLine(outp, input.subbuffer(y * lineBytes), prevLine, lineBytes, byteWidth, PNGFilter(fType))
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for x in 0..255: count[x] = 0
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for x in 0..lineBytes-1:
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inc count[ord(attempt[fType][x])]
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@ -2826,7 +2826,7 @@ proc filterPredefined(output: var DataBuf, input: DataBuf, w, h, bpp: int, state
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let fType = ord(state.predefinedFilters[y])
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output[outindex] = chr(fType) #filter type byte
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var outp = output.subbuffer(outindex + 1)
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filterScanLine(outp, input.subbuffer(inindex), prevLine, lineBytes, byteWidth, PNGFilter0(fType))
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filterScanLine(outp, input.subbuffer(inindex), prevLine, lineBytes, byteWidth, PNGFilter(fType))
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prevLine = input.subbuffer(inindex)
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proc filterBruteForce(output: var DataBuf, input: DataBuf, w, h, bpp: int) =
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@ -2856,7 +2856,7 @@ proc filterBruteForce(output: var DataBuf, input: DataBuf, w, h, bpp: int) =
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for fType in 0..4:
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#let testSize = attempt[fType].len
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var outp = initBuffer(attempt[fType])
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filterScanline(outp, input.subbuffer(y * lineBytes), prevLine, lineBytes, byteWidth, PNGFilter0(fType))
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filterScanline(outp, input.subbuffer(y * lineBytes), prevLine, lineBytes, byteWidth, PNGFilter(fType))
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size[fType] = 0
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var nz = nzDeflateInit(attempt[fType])
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@ -3385,24 +3385,24 @@ when not defined(js):
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debugEcho getCurrentExceptionMsg()
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result = false
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proc getFilterTypesInterlaced(png: PNG): seq[string] =
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proc getFilterTypesInterlaced(png: PNG): seq[seq[PNGFilter]] =
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var header = PNGHeader(png.getChunk(IHDR))
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var idat = PNGData(png.getChunk(IDAT))
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if header.interlaceMethod == IM_NONE:
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result = newSeq[string](1)
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result[0] = ""
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result = newSeq[seq[PNGFilter]](1)
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result[0] = @[]
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#A line is 1 filter byte + all pixels
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let lineBytes = 1 + idatRawSize(header.width, 1, header)
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var i = 0
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while i < idat.idat.len:
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result[0].add idat.idat[i]
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result[0].add PNGFilter(idat.idat[i].int)
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inc(i, lineBytes)
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else:
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result = newSeq[string](7)
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result = newSeq[seq[PNGFilter]](7)
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for j in 0..6:
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result[j] = ""
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result[j] = @[]
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var w2 = (header.width - ADAM7_IX[j] + ADAM7_DX[j] - 1) div ADAM7_DX[j]
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var h2 = (header.height - ADAM7_IY[j] + ADAM7_DY[j] - 1) div ADAM7_DY[j]
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if(ADAM7_IX[j] >= header.width) or (ADAM7_IY[j] >= header.height):
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@ -3412,10 +3412,10 @@ proc getFilterTypesInterlaced(png: PNG): seq[string] =
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let lineBytes = 1 + idatRawSize(w2, 1, header)
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var pos = 0
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for i in 0..h2-1:
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result[j].add idat.idat[pos]
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result[j].add PNGFilter(idat.idat[pos].int)
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inc(pos, linebytes)
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proc getFilterTypes*(png: PNG): string =
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proc getFilterTypes*(png: PNG): seq[PNGFilter] =
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var passes = getFilterTypesInterlaced(png)
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if passes.len == 1:
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@ -3425,7 +3425,7 @@ proc getFilterTypes*(png: PNG): string =
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#Interlaced. Simplify it: put pass 6 and 7 alternating in the one vector so
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#that one filter per scanline of the uninterlaced image is given, with that
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#filter corresponding the closest to what it would be for non-interlaced image.
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result = ""
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result = @[]
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for i in 0..header.height-1:
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if (i mod 2) == 0: result.add passes[5][i div 2]
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else: result.add passes[6][i div 2]
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@ -438,7 +438,7 @@ proc testPaletteFilterTypesZero() =
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assertEquals(17, filterTypes.len)
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for i in 0..16:
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assertEquals(0.chr, filterTypes[i])
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assertEquals(FLT_NONE, filterTypes[i])
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proc testComplexPNG() =
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echo "testComplexPNG"
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@ -485,13 +485,18 @@ proc testPredefinedFilters() =
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var state = makePNGEncoder()
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state.filterStrategy = LFS_PREDEFINED
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state.filterPaletteZero = false
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state.predefinedFilters = repeat(chr(3), h) #everything to filter type '3'
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# everything to filter type 'FLT_AVERAGE'
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state.predefinedFilters = newSeq[PNGFilter](h)
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for i in 0..<h:
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state.predefinedFilters[i] = FLT_AVERAGE
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var png = encodePNG(image.data, w, h, state)
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var outFilters = png.getFilterTypes()
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assertEquals(h, outFilters.len)
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for i in 0..<h:
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assertEquals(chr(3), outFilters[i])
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assertEquals(FLT_AVERAGE, outFilters[i])
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# Tests combinations of various colors in different orders
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proc testFewColors() =
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