[pdftex] graphic{s,x} PNG + pdflatex bug

[Jim Diamond]

On Thu, May  6, 2010 at 15:36 (-0300), George N. White III wrote:

> On Thu, May 6, 2010 at 2:33 PM, Taco Hoekwater <taco at elvenkind.com> wrote:
>> Nico Schlömer wrote:

>>> Hi all,

>>> I experienced a weird bug using \includegraphics of the graphicx
>>> package with pdflatex 1.40.10.

>>> I try to load the attached PNG file, and unlike with other PNG files,
>>> pdflatex would just bail out with

>>> ==================== *snip* ====================
>>> [...]
>>> [Loading MPS to PDF converter (version 2006.09.02).]
>>> )
>>> ! Dimension too large.
>>> <argument> \wd \@tempboxa
>>> l.7 \includegraphics{img1.png}
>>> ?
>>> ==================== *snap* ====================

>>> David Carlisle, maintainer of graphicx, suggests that may be a bug in
>>> pdflatex -- What do you reckon?

>> Well, this png specifies a resolution of 0.9906 pixel per inch so it
>> has natural sizes of about 252 inch (6.4m). So in my opinion something
>> *is* wrong with the png.

>> Best wishes,
>> Taco

> $ identify -verbose img1.png |head
> Image: img1.png
> Format: PNG (Portable Network Graphics)
> Class: DirectClass
> Geometry: 250x250+0+0
> Resolution: 0.39x0.39
> Print size: 641.026x641.026
> Units: PixelsPerCentimeter

> I loaded the PNG in Adobe Photoshop and saved it as  img2.png:

> $ identify -verbose img2.png |head
> Image: img2.png
> Format: PNG (Portable Network Graphics)
> Class: DirectClass
> Geometry: 250x250+0+0
> Resolution: 0.39x0.39
> Print size: 641.026x641.026
> Units: PixelsPerCentimeter

> $ pngcheck -vt img1.png
> File: img1.png (92868 bytes)
> chunk IHDR at offset 0x0000c, length 13
>     250 x 250 image, 32-bit RGB+alpha, non-interlaced
> chunk sBIT at offset 0x00025, length 4
> red = 8 = 0x08, green = 8 = 0x08, blue = 8 = 0x08, alpha = 8 = 0x08
> chunk pHYs at offset 0x00035, length 9: 39x39 pixels/meter (1 dpi)
> chunk IDAT at offset 0x0004a, length 8192
> zlib: deflated, 32K window, default compression
> chunk IDAT at offset 0x02056, length 8192
> chunk IDAT at offset 0x04062, length 8192
> chunk IDAT at offset 0x0606e, length 8192
> chunk IDAT at offset 0x0807a, length 8192
> chunk IDAT at offset 0x0a086, length 8192
> chunk IDAT at offset 0x0c092, length 8192
> chunk IDAT at offset 0x0e09e, length 8192
> chunk IDAT at offset 0x100aa, length 8192
> chunk IDAT at offset 0x120b6, length 8192
> chunk IDAT at offset 0x140c2, length 8192
> chunk IDAT at offset 0x160ce, length 2530
> chunk IEND at offset 0x16abc, length 0
> No errors detected in img1.png (16 chunks, 62.9% compression).
> $ pngcheck -vt img2.png
> File: img2.png (92076 bytes)
> chunk IHDR at offset 0x0000c, length 13
>     250 x 250 image, 32-bit RGB+alpha, non-interlaced
> chunk bKGD at offset 0x00025, length 6
> red = 0x00ff, green = 0x00ff, blue = 0x00ff
> chunk pHYs at offset 0x00037, length 9: 39x39 pixels/meter (1 dpi)
> chunk vpAg at offset 0x0004c, length 9
> unknown private, ancillary, safe-to-copy chunk
> chunk IDAT at offset 0x00061, length 32768
> zlib: deflated, 32K window, maximum compression
> chunk IDAT at offset 0x0806d, length 32768
> chunk IDAT at offset 0x10079, length 26301
> chunk tEXt at offset 0x16742, length 37, keyword: create-date
>     2010-05-06T12:39:23-03:00
> chunk tEXt at offset 0x16773, length 37, keyword: modify-date
>     2010-05-06T12:35:33-03:00
> chunk IEND at offset 0x167a4, length 0
> No errors detected in img2.png (10 chunks, 63.2% compression).

> Both versions look the same using Imagemagick's display,
> but img2.png does not give the error, so image size does
> not explain the error.

Did you compare the rest of the output of "identify -verbose" ?  There
may be something illuminating there.  As your pngcheck output shows,
the photoshop version is quite a bit different.

Cheers.
				Jim