Color-/Lineshifts under Windows?

[Hauke Heibel]

Hi,

I tried to debug this but did not succeed but want to let you know
about my findings. I thought the error might be coming from
openslide-ops-jpeg.h so I reverted to file to the oldest version being
windows compatible and nothing changed. I double checked, that the
jpeg is correctly read by the function read_from_one_jpeg(...) and
that seems to be the case. It is though funny, that three different
programs (xnview, photoshop, openslide resp. jpeglib) give me three
different results when it comes to the color of pixel (48,204) of the
file Data0014.dat - no clue why this should and could happen.

The file test7-09.ppm is generated from Data0014.dat. I saved the
Data0014.dat as a proper jpeg and loaded Data0014.jpeg and
test07-09.ppm into Gimp and tried to overlay the two files - it is
impossible. The problem is that even the shape of the cells changed in
test7-09.ppm and not only the colors.

I am not yet sure how to properly debug in OpenSlide since I am always
a bit confused about where the actual data is written to the
destination buffer? Is it in read_tile? Do I understand correctly,
that read_tile is writing one tile to the destination buffer?

A last thing I tried is that I changed the call to
cairo_image_surface_create_for_data(...) in the function read_tile.
The color format was set to CAIRO_FORMAT_RGB24 and I was thinking
CAIRO_FORMAT_RGBA24 would be better, since actually, the data is RGBA,
right?

That's all I could come up with so far.

Regards,
Hauke

2010/8/4 Marco Feuerstein <feuerste at cs.tum.edu>:
> Adam,
> thanks for looking into that problem.
> I hope you can fix it easily. Please let me know if I can test anything here.
> Marco
>
>> -----Original Message-----
>> From: Adam Goode [mailto:agoode at andrew.cmu.edu]
>> Sent: Mittwoch, 4. August 2010 03:06
>> To: Marco Feuerstein
>> Cc: openslide-users at lists.andrew.cmu.edu
>> Subject: Re: Color-/Lineshifts under Windows?
>>
>> Marco,
>>
>> Glad it fixes the problem, at least partially. On Windows I never run
>> test.c so I never see this.
>>
>> The black dots are more troubling, Mirax is a difficult format to
>> render, and I have had many such bugs like this in the past. After
>> trying it, I do see the dots on Linux.
>>
>> I think I know why the dots are visible now and not before, I will try
>> to look into it. At the very least, I will record a bug. :)
>>
>>
>> Thanks,
>>
>> Adam
>
> _______________________________________________
> openslide-users mailing list
> openslide-users at lists.andrew.cmu.edu
> https://lists.andrew.cmu.edu/mailman/listinfo/openslide-users
>