#SNG: from basn0g04-31.png
IHDR {
    width: 31; height: 31; bitdepth: 8;
    using grayscale;
}
gAMA {1.0000}
IMAGE {
    pixels hex
00000000111111112222222233333333444444445555555566666666777777
00000000111111112222222233333333444444445555555566666666777777
00000000111111112222222233333333444444445555555566666666777777
00000000111111112222222233333333444444445555555566666666777777
11111111222222223333333344444444555555556666666677777777888888

#SNG: from basn0g02-29.png
IHDR {
    width: 29; height: 29; bitdepth: 8;
    using grayscale;
}
gAMA {1.0000}
IMAGE {
    pixels hex
0000000055555555aaaaaaaaffffffff0000000055555555aaaaaaaaff
0000000055555555aaaaaaaaffffffff0000000055555555aaaaaaaaff
0000000055555555aaaaaaaaffffffff0000000055555555aaaaaaaaff
0000000055555555aaaaaaaaffffffff0000000055555555aaaaaaaaff
55555555aaaaaaaaffffffff0000000055555555aaaaaaaaffffffff00

#SNG: from basn3p04-31i.png
IHDR {
    width: 31; height: 31; bitdepth: 4;
    using color palette;
}
gAMA {1.0000}
PLTE {
    ( 34,  0,255)     # rgb = (0x22,0x00,0xff)
    (  0,255,255)     # rgb = (0x00,0xff,0xff)
    (136,  0,255)     # rgb = (0x88,0x00,0xff)
    ( 34,255,  0)     # rgb = (0x22,0xff,0x00)
    (  0,153,255)     # rgb = (0x00,0x99,0xff)
    (255,102,  0)     # rgb = (0xff,0x66,0x00)
    (221,  0,255)     # rgb = (0xdd,0x00,0xff)

#SNG: from basn0g01-30.png
IHDR {
    width: 30; height: 30; bitdepth: 8;
    using grayscale;
}
gAMA {1.0000}
IMAGE {
    pixels hex
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
ffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
ffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000
ffffffff0000ffffffffffff0000ffffffffffffffffffffffffff000000

#SNG: from basn3p08-trns.png
IHDR {
    width: 32; height: 32; bitdepth: 8;
    using color palette;
}
gAMA {1.0000}
PLTE {
    (255,  3,  7)     # rgb = (0xff,0x03,0x07)
    (255,  4,  7)     # rgb = (0xff,0x04,0x07)
    (255,  9,  7)     # rgb = (0xff,0x09,0x07)
    (217, 14,  7)     # rgb = (0xd9,0x0e,0x07)
    (255, 14,  7)     # rgb = (0xff,0x0e,0x07)
    (  2, 22, 19)     # rgb = (0x02,0x16,0x13)
    (255, 26,  7)     # rgb = (0xff,0x1a,0x07)

converted it to the 8-bit paletted image with alpha values in tRNS chunk.

The *.sng files in this directory were generated from the *.png files by the
sng command-line tool and some hand editing. The files basn0g0{1,2,4}.sng and
ftbbn0g0{1,2,4}.sng were actually generated by first converting the PNG to a
bitdepth of 8 and then running sng on them. basn4a08.sng was generated from a

		}

		piper, pipew := io.Pipe()
		pb := bufio.NewScanner(piper)
		go sng(pipew, fn, img)
		defer piper.Close()

		// Read the .sng file.
		sf, err := os.Open("testdata/pngsuite/" + fn + ".sng")
		if err != nil {
			t.Error(fn, err)
			continue
		}
		defer sf.Close()
		sb := bufio.NewScanner(sf)

		// Compare the two, in SNG format, line by line.
		for {
			pdone := !pb.Scan()
			sdone := !sb.Scan()