[PNG Suite icon] PNG Suite from Willem van Schaik

This is (an older copy of) Willem van Schaik's suite of PNG icons for testing PNG decoder engines, PNG viewers, and PNG browsers. Most of the icons are 32x32, and they run the gamut from 1-bit to 64-bit depth; grayscale, colormapped and truecolor; interlaced or not; and with or without simple transparency, full transparency (alpha channel), background chunks, histograms, gamma or chromaticity data, comments, time stamps, and physical pixel dimensions. There are even three invalid PNG images included, one 0x0 in size and the other two corrupted by non-binary transfers.

Archives containing the full 2011 suite can be found on Willem's own, multi-page PngSuite site, which also includes GIF images for comparison.

Note that all images here are referenced with the standard HTML IMG tag, not OBJECT or Netscape's EMBED; that means this page will not display properly with any PNG plug-in due to bugs (er, that is, limitations) in Netscape's plug-in architecture. (This comment was relevant a decade ago...nowadays, never mind.)
version of this page with GIF images for comparison. (Note that the gamma-correction PNG images will necessarily look somewhat different from the corresponding GIF images unless your display characteristics are similar to those of a NeXT.) Willem previously also had an older, separate set of pages (using EMBED) for testing Netscape and/or Internet Explorer PNG plug-ins. -->

Basic PNG image types, non-interlaced* and interlaced:

Alpha-channel images with and without background chunks:

The two rows should look identical in browsers that handle transparency correctly. In a normal image viewer (one with no preferred background, i.e., not a web browser), the top four icons should have backgrounds of yellow, white, gray and black, respectively; this will be visible on the left sides of all four images and around the periphery of the first and third icons (the two "X" images). The icons in the bottom row will generally default to a black background in non-browser image viewers.

Histogram-chunk images:

Chromaticity-chunk images:

Images with different gamma chunks:

All six columns will look essentially identical (not counting the printed numbers) if your browser does gamma correction. Within each icon, the two rightmost bars (one solid color and one with alternating black and max-intensity horizontal lines) will appear to be approximately the same color, assuming your browser's gamma correction is correct for your monitor. If your browser just dumps the raw pixel data on screen, the icons to the left will have darker bars than those to the right.

Images with different compression filters:

Images with comments or time stamps:

Images with ancillary (suggested) palettes:

Images with significant-bits chunks, both colormapped and truecolor:

Images with non-square pixels and/or pixels with physical dimensions:

1x1 to 9x9 and 32x32 to 40x40 images, non-interlaced and interlaced:

Images with simple transparency and various background chunks:

Images with different numbers and sizes of IDAT chunks:

Images with different compression levels:

Invalid and/or corrupted PNG images (links only):


Excerpt from PNG Suite Documentation

3.1     Basic format test files (non-interlaced)

        basn0g01    -   black & white
        basn0g02    -   2 bit (4 level) grayscale
        basn0g04    -   4 bit (16 level) grayscale
        basn0g08    -   8 bit (256 level) grayscale
        basn0g16    -   16 bit (64k level) grayscale
        basn2c08    -   3x8 bits rgb color
        basn2c16    -   3x16 bits rgb color
        basn3p01    -   1 bit (2 color) paletted
        basn3p02    -   2 bit (4 color) paletted
        basn3p04    -   4 bit (16 color) paletted
        basn3p08    -   8 bit (256 color) paletted
        basn4a08    -   8 bit grayscale + 8 bit alpha-channel
        basn4a16    -   16 bit grayscale + 16 bit alpha-channel
        basn6a08    -   3x8 bits rgb color + 8 bit alpha-channel
        basn6a16    -   3x16 bits rgb color + 16 bit alpha-channel

3.2     Basic format test files (Adam-7 interlaced)

        basi0g01    -   black & white
        basi0g02    -   2 bit (4 level) grayscale
        basi0g04    -   4 bit (16 level) grayscale
        basi0g08    -   8 bit (256 level) grayscale
        basi0g16    -   16 bit (64k level) grayscale
        basi2c08    -   3x8 bits rgb color
        basi2c16    -   3x16 bits rgb color
        basi3p01    -   1 bit (2 color) paletted
        basi3p02    -   2 bit (4 color) paletted
        basi3p04    -   4 bit (16 color) paletted
        basi3p08    -   8 bit (256 color) paletted
        basi4a08    -   8 bit grayscale + 8 bit alpha-channel
        basi4a16    -   16 bit grayscale + 16 bit alpha-channel
        basi6a08    -   3x8 bits rgb color + 8 bit alpha-channel
        basi6a16    -   3x16 bits rgb color + 16 bit alpha-channel

3.3     Size test files

        s01n3p01    -   1x1 paletted file, no interlacing
        s02n3p01    -   2x2 paletted file, no interlacing
        s03n3p01    -   3x3 paletted file, no interlacing
        s04n3p01    -   4x4 paletted file, no interlacing
        s05n3p02    -   5x5 paletted file, no interlacing
        s06n3p02    -   6x6 paletted file, no interlacing
        s07n3p02    -   7x7 paletted file, no interlacing
        s08n3p02    -   8x8 paletted file, no interlacing
        s09n3p02    -   9x9 paletted file, no interlacing
        s32n3p04    -   32x32 paletted file, no interlacing
        s33n3p04    -   33x33 paletted file, no interlacing
        s34n3p04    -   34x34 paletted file, no interlacing
        s35n3p04    -   35x35 paletted file, no interlacing
        s36n3p04    -   36x36 paletted file, no interlacing
        s37n3p04    -   37x37 paletted file, no interlacing
        s38n3p04    -   38x38 paletted file, no interlacing
        s39n3p04    -   39x39 paletted file, no interlacing
        s40n3p04    -   40x40 paletted file, no interlacing

        s01i3p01    -   1x1 paletted file, interlaced
        s02i3p01    -   2x2 paletted file, interlaced
        s03i3p01    -   3x3 paletted file, interlaced
        s04i3p01    -   4x4 paletted file, interlaced
        s05i3p02    -   5x5 paletted file, interlaced
        s06i3p02    -   6x6 paletted file, interlaced
        s07i3p02    -   7x7 paletted file, interlaced
        s08i3p02    -   8x8 paletted file, interlaced
        s09i3p02    -   9x9 paletted file, interlaced
        s32i3p04    -   32x32 paletted file, interlaced
        s33i3p04    -   33x33 paletted file, interlaced
        s34i3p04    -   34x34 paletted file, interlaced
        s35i3p04    -   35x35 paletted file, interlaced
        s36i3p04    -   36x36 paletted file, interlaced
        s37i3p04    -   37x37 paletted file, interlaced
        s38i3p04    -   38x38 paletted file, interlaced
        s39i3p04    -   39x39 paletted file, interlaced
        s40i3p04    -   40x40 paletted file, interlaced

3.4     Alpha-channel (and background) test files

        bgbn4a08    -   8 bit grayscale, alpha, black background chunk
        bggn4a16    -   16 bit grayscale, alpha, gray background chunk
        bgwn6a08    -   3x8 bits rgb color, alpha, white background chunk
        bgyn6a16    -   3x16 bits rgb color, alpha, yellow background chunk

        bgai4a08    -   8 bit grayscale, alpha, no background chunk
        bgai4a16    -   16 bit grayscale, alpha, no background chunk
        bgan6a08    -   3x8 bits rgb color, alpha, no background chunk
        bgan6a16    -   3x16 bits rgb color, alpha, no background chunk

3.5     Transparency (and background) test files

        tp0n1g08    -   not transparent for reference (logo on gray)
        tbbn1g04    -   transparent, black background chunk
        tbwn1g16    -   transparent, white background chunk
        tp0n2c08    -   not transparent for reference (logo on gray)
        tbrn2c08    -   transparent, red background chunk
        tbgn2c16    -   transparent, green background chunk
        tbbn2c16    -   transparent, blue background chunk
        tp0n3p08    -   not transparent for reference (logo on gray)
        tp1n3p08    -   transparent, but no background chunk
        tbbn3p08    -   transparent, black background chunk
        tbgn3p08    -   transparent, light-gray background chunk 
        tbwn3p08    -   transparent, white background chunk
        tbyn3p08    -   transparent, yellow background chunk

3.6     Gamma test files

        g03n0g16    -   grayscale, file-gamma = 0.35
        g04n0g16    -   grayscale, file-gamma = 0.45
        g05n0g16    -   grayscale, file-gamma = 0.55
        g07n0g16    -   grayscale, file-gamma = 0.70
        g10n0g16    -   grayscale, file-gamma = 1.00
        g25n0g16    -   grayscale, file-gamma = 2.50
        g03n2c08    -   color, file-gamma = 0.35
        g04n2c08    -   color, file-gamma = 0.45
        g05n2c08    -   color, file-gamma = 0.55
        g07n2c08    -   color, file-gamma = 0.70
        g10n2c08    -   color, file-gamma = 1.00
        g25n2c08    -   color, file-gamma = 2.50
        g03n3p04    -   paletted, file-gamma = 0.35
        g04n3p04    -   paletted, file-gamma = 0.45
        g05n3p04    -   paletted, file-gamma = 0.55
        g07n3p04    -   paletted, file-gamma = 0.70
        g10n3p04    -   paletted, file-gamma = 1.00
        g25n3p04    -   paletted, file-gamma = 2.50

3.7     Filtering test files

        f00n0g08    -   grayscale, no interlacing, filter-type 0 
        f01n0g08    -   grayscale, no interlacing, filter-type 1
        f02n0g08    -   grayscale, no interlacing, filter-type 2
        f03n0g08    -   grayscale, no interlacing, filter-type 3
        f04n0g08    -   grayscale, no interlacing, filter-type 4
        f00n2c08    -   color, no interlacing, filter-type 0 
        f01n2c08    -   color, no interlacing, filter-type 1
        f02n2c08    -   color, no interlacing, filter-type 2
        f03n2c08    -   color, no interlacing, filter-type 3
        f04n2c08    -   color, no interlacing, filter-type 4

3.8     Additional palette chunk test files

        pp0n2c16    -   six-cube palette-chunk in true-color image
        pp0n6a08    -   six-cube palette-chunk in true-color+alpha image
        ps1n0g08    -   six-cube suggested palette (1 byte) in grayscale image
        ps1n2c16    -   six-cube suggested palette (1 byte) in true-color image
        ps2n0g08    -   six-cube suggested palette (2 bytes) in grayscale image
        ps2n2c16    -   six-cube suggested palette (2 bytes) in true-color image

3.9     Ancillary chunks test files

        cs5n2c08    -   color, 5 significant bits
        cs8n2c08    -   color, 8 significant bits (reference)
        cs3n2c16    -   color, 13 significant bits
        cs3n3p08    -   paletted, 3 significant bits
        cs5n3p08    -   paletted, 5 significant bits
        cs8n3p08    -   paletted, 8 significant bits (reference)

        cdfn2c08    -   physical pixel dimensions, 8x32 flat pixels
        cdhn2c08    -   physical pixel dimensions, 32x8 high pixels
        cdsn2c08    -   physical pixel dimensions, 8x8 square pixels
        cdun2c08    -   physical pixel dimensions, 1000 pixels per 1 meter

        ccwn2c08    -   chroma chunk w:0.3127,0.3290 r:0.64,0.33 g:0.30,0.60 b:0.15,0.06
        ccwn3p08    -   chroma chunk w:0.3127,0.3290 r:0.64,0.33 g:0.30,0.60 b:0.15,0.06

        ch1n3p04    -   histogram 15 colors
        ch2n3p08    -   histogram 256 colors

        cm7n0g04    -   modification time, 01-jan-1970 00:00:00
        cm9n0g04    -   modification time, 31-dec-1999 23:59:59
        cm0n0g04    -   modification time, 01-jan-2000 12:34:56

        ct0n0g04    -   no textual data
        ct1n0g04    -   with textual data
        ctzn0g04    -   with compressed textual data

3.10    Chunk ordering

        oi1n0g16    -   grayscale mother image with 1 idat-chunk
        oi2n0g16    -   grayscale image with 2 idat-chunks
        oi4n0g16    -   grayscale image with 4 unequal sized idat-chunks
        oi9n0g16    -   grayscale image with all idat-chunks length one
        oi1n2c16    -   color mother image with 1 idat-chunk
        oi2n2c16    -   color image with 2 idat-chunks
        oi4n2c16    -   color image with 4 unequal sized idat-chunks
        oi9n2c16    -   color image with all idat-chunks length one

3.11    Compression level

        z00n2c08    -   color, no interlacing, compression level 0 (none)
        z03n2c08    -   color, no interlacing, compression level 3
        z06n2c08    -   color, no interlacing, compression level 6 (default)
        z09n2c08    -   color, no interlacing, compression level 9 (maximum)

3.12    Corrupted files

        x00n0g01    -   empty 0x0 grayscale file 
        xcrn0g04    -   added cr bytes
        xlfn0g04    -   converted cr bytes to lf and removed all NULs

Here are some related PNG pages at this site:

*Or, as Vince Sabio would say, "straight-laced." :-)
[primary site hosted by SourceForge] Last modified 30 April 2011.

HTML copyright © 1996-2011 Greg Roelofs.
PNG Suite images and documentation copyright © 1995-1998 (and 2011 for the newest set) Willem van Schaik.