pngcheck is a command-line utility to check PNG image files for validity and to give information about metadate inside the file (apart from the actual image data).
This unofficial version is forked from pngcheck 3.0.3 (see 3.0.3 README) and adds the following new features:
- Coding Independent Code Points
cICP - Mastering Display Color Volume
mDCV - Content Light Level Information
cLLI
It also warns if eXIf is found after the image data IDAT,
which will be ignored by web browsers
and is no longer valid in PNG Third Edition.
Sample usage:
$ pngcheck -c -v test_pattern-PQ.png
File: test_pattern-PQ.png (12033 bytes)
chunk IHDR at offset 0x0000c, length 13
1024 x 1024 image, 48-bit RGB, non-interlaced
chunk iCCP at offset 0x00025, length 2181
profile name = 1, compression method = 0 (deflate)
compressed profile = 2178 bytes
chunk cHRM at offset 0x008b6, length 32
White x = 0.3127 y = 0.329, Red x = 0.708 y = 0.292
Green x = 0.17 y = 0.797, Blue x = 0.131 y = 0.046
chunk cICP at offset 0x008e2, length 4
Rec. ITU-R BT.2100-2 perceptual quantization (PQ) system
White x = 0.3127 y = 0.329, Red x = 0.708 y = 0.292
Green x = 0.17 y = 0.797, Blue x = 0.131 y = 0.046
Full range
chunk cLLi at offset 0x008f2, length 8
Old version of CLLI, do not use
ERRORS DETECTED in test_pattern-PQ.png