66291 - weird warning "libpng warning: Incomplete compressed datastream in iCCP chunk"

Status: VERIFIED INVALID

(Core :: Graphics: ImageLib, defect)

Description

[Henrik Gemal]

I'm not sure if this is a bug or not, but going to:
http://www.mcafee.dk/dat/
put this in the console:
libpng warning: Incomplete compressed datastream in iCCP chunk
libpng warning: Incomplete compressed datastream in iCCP chunk
libpng warning: Incomplete compressed datastream in iCCP chunk
Document http://www.mcafee.dk/dat/ loaded successfully

Is that because of corrupted images?

Build 20010122

Comment 1

[HJ]

Sorry but I can't confirm with build 2001012205 on WinNT4, what build are you
using? (I'm missing the build time)

Comment 2

[Henrik Gemal]

using build 2001012304 on Win2k

Comment 3

[tenthumbs]

Some of the PNGs are, indeed, corrupt. For example,

File: s020h.png (2835 bytes)
  chunk IHDR at offset 0x0000c, length 13
    1 x 20 image, 24-bit RGB, non-interlaced
  chunk iCCP at offset 0x00025, length 2615
    profile name = Photoshop ICC profile, compression method = 0
(deflate)
    compressed profile = 2592 bytes
  chunk gAMA at offset 0x00a68, length 4: 0.45454
  chunk cHRM at offset 0x00a78, length 32
    White x = 0.31269 y = 0.32899,  Red x = 0.63999 y = 0.32998
    Green x = 0.29998 y = 0.59999,  Blue x = 0.14999 y = 0.05999
  chunk IDAT at offset 0x00aa4, length 91
    zlib:  deflated, 32K window, default compression
  chunk IEND at offset 0x00b0b, length 0
No errors detected in s020h.png (-4625.0% compression).

has a bad iCCP chunk.

The message comes from deep within libpng (pngrutil.c). Whether you see
it would depend on whether your Mozilla uses its own libpng or the
system one. In addition, there are many options for building the
standard library.

FWIW, libpng-1.0.9beta10 introduces an additional warning for this
image:

libpng warning: Incomplete compressed datastream in iCCP chunk
libpng warning: Ignoring truncated iCCP profile.

This might be more informative or might be more scary to the typical
user.

This isn't really a Mozilla bug. The only question is whether to change
Mozilla's libpng warning messages.

BTW, notice all the overhead in the file for a 1x20 image.

Comment 4

[Stuart Parmenter]

can this be marked invalid since the images are corrupt?

Comment 5

[tenthumbs]

The images aren't corrupt, only an ancillary chunk. If mozilla renders the image
anyway then the warnings are just that and the only real issue is whether the warning
messages could be better.

If mozilla won't render the image, it's a bug.

Comment 6

[pnunn]

All pnunn bugs reassigned to Pav, who is taking over
the imglib.

Comment 7

[Stuart Parmenter]

the error comes directly from libpng.. not a whole lot I can do about the error 
message.

Comment 8

[Terri Preston]

pavlov, should we close this as invalid then?

Comment 9

[Stuart Parmenter]

sure

Comment 10

[Henrik Gemal]

invalid = ok...