2015-08-28 15:56:55 +00:00
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#nimPNG
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Portable Network Graphics Encoder and Decoder written in Nim
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2015-09-03 04:56:22 +00:00
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store lossless image with good compression
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2015-08-28 15:56:55 +00:00
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all PNG standard color mode are supported:
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- LCT_GREY = 0, # greyscale: 1,2,4,8,16 bit
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- LCT_RGB = 2, # RGB: 8,16 bit
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- LCT_PALETTE = 3, # palette: 1,2,4,8 bit
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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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both interlaced and non-interlaced mode supported
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recognize all PNG standard chunks:
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IHDR, IEND, PLTE, IDAT, tRNS, bKGD, pHYs, tIME, iTXt, zTXt
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tEXt, gAMA, cHRM, sRGB, iCCP, sBIT, sPLT, hIST
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unknown chunks will be handled properly
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the following chunks are supported (generated/interpreted) by both encoder and decoder:
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- IHDR: header information
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- PLTE: color palette
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- IDAT: pixel data
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- IEND: the final chunk
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- tRNS: transparency for palettized images
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- tEXt: textual information
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- zTXt: compressed textual information
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- iTXt: international textual information
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- bKGD: suggested background color
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- pHYs: physical dimensions
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- tIME: modification time
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the following chunks are parsed correctly, but not used by decoder:
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cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT
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Supported color conversions:
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- anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA
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- any grey or grey+alpha, to grey or grey+alpha
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- anything to a palette, as long as the palette has the requested colors in it
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- removing alpha channel
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2015-09-03 04:56:22 +00:00
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- higher to smaller bitdepth, and vice versa
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###Feature planned:
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- streaming for progressive loading
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