nanogui: Thread: PNG image with white pixels

Hi all,

I'm using FLTK 2.0, nxlib-0.45 and microwindows 0.91, and I'm having a
problem showing png images.
When the picture has a pixel totally white or almost white, it appears black
on the screen.
I'm having a similar problem using nxview, but this time only the pixels
with the color totally white (R=255, G=255, B=255) appears black.
I've tried to debug it, but I can't find what is wrong.
Does anyone have the same problem? Any ideas for fixing it?

Thanks in advance,

Rafael C. Schwarz

This is an old problem that was fixed with latest version (CVS).
Martin


-----Original Message-----
From: Rafael Schwarz ####@####.#### 
Sent: Thursday, December 18, 2008 5:27 AM
To: ####@####.####
Subject: [nanogui] PNG image with white pixels

Hi all,

I'm using FLTK 2.0, nxlib-0.45 and microwindows 0.91, and I'm having a
problem showing png images.
When the picture has a pixel totally white or almost white, it appears
black
on the screen.
I'm having a similar problem using nxview, but this time only the pixels
with the color totally white (R=255, G=255, B=255) appears black.
I've tried to debug it, but I can't find what is wrong.
Does anyone have the same problem? Any ideas for fixing it?

Thanks in advance,

Rafael C. Schwarz

Thanks Kajdas and sorry for posting and old problem,
It happened because I use an microwindows version that is prepared to
cross-compile for Altera Nios2 and is entire in another version control
tree, where it's not updated with CVS version of microwindows.
I don't know how is the best way to proceed now for update it. Maybe create
a patch that changes just the files that are source code, this way I won't
have problems to compile it again.

Anyway, thanks for the help. If anyone knows how is the correct way to
update my microwindos folder without losing the changes for the
cross-compile, I'm open for ideas.

Rafael C. Schwarz

2008/12/18 Martin Kajdas ####@####.####

> This is an old problem that was fixed with latest version (CVS).
> Martin
>
>
> -----Original Message-----
> From: Rafael Schwarz ####@####.####
> Sent: Thursday, December 18, 2008 5:27 AM
> To: ####@####.####
> Subject: [nanogui] PNG image with white pixels
>
> Hi all,
>
> I'm using FLTK 2.0, nxlib-0.45 and microwindows 0.91, and I'm having a
> problem showing png images.
> When the picture has a pixel totally white or almost white, it appears
> black
> on the screen.
> I'm having a similar problem using nxview, but this time only the pixels
> with the color totally white (R=255, G=255, B=255) appears black.
> I've tried to debug it, but I can't find what is wrong.
> Does anyone have the same problem? Any ideas for fixing it?
>
> Thanks in advance,
>
> Rafael C. Schwarz
>

You can always implement the fix yourself.

It is only a few lines long. I think it is in loadimage.c or something
similar.

Martin

 

 

________________________________

From: Rafael Schwarz ####@####.#### 
Sent: Thursday, December 18, 2008 9:34 AM
To: Martin Kajdas
Cc: ####@####.####
Subject: Re: [nanogui] PNG image with white pixels

 

Thanks Kajdas and sorry for posting and old problem,

It happened because I use an microwindows version that is prepared to
cross-compile for Altera Nios2 and is entire in another version control
tree, where it's not updated with CVS version of microwindows.

I don't know how is the best way to proceed now for update it. Maybe
create a patch that changes just the files that are source code, this
way I won't have problems to compile it again.

 

Anyway, thanks for the help. If anyone knows how is the correct way to
update my microwindos folder without losing the changes for the
cross-compile, I'm open for ideas.

 

Rafael C. Schwarz

2008/12/18 Martin Kajdas ####@####.####

This is an old problem that was fixed with latest version (CVS).
Martin



-----Original Message-----
From: Rafael Schwarz ####@####.####
Sent: Thursday, December 18, 2008 5:27 AM
To: ####@####.####
Subject: [nanogui] PNG image with white pixels

Hi all,

I'm using FLTK 2.0, nxlib-0.45 and microwindows 0.91, and I'm having a
problem showing png images.
When the picture has a pixel totally white or almost white, it appears
black
on the screen.
I'm having a similar problem using nxview, but this time only the pixels
with the color totally white (R=255, G=255, B=255) appears black.
I've tried to debug it, but I can't find what is wrong.
Does anyone have the same problem? Any ideas for fixing it?

Thanks in advance,

Rafael C. Schwarz

 

> It is only a few lines long. I think it is in loadimage.c or something
similar.

Yes - the bug appeared when an alpha channel patch was accepted,
and then white 255,255,255 with alpha 255 (all 1 bits) was
the same as a -1 compare, which was used as the transparent
color comparator (transcolor).  The draw routine thought the
color was transparent, and didn't draw it, usually resulting in
black, the default background color.

Regards,

Greg





 

Thanks Kajdas and sorry for posting and old problem,

It happened because I use an microwindows version that is prepared to
cross-compile for Altera Nios2 and is entire in another version control
tree, where it's not updated with CVS version of microwindows.

I don't know how is the best way to proceed now for update it. Maybe
create a patch that changes just the files that are source code, this
way I won't have problems to compile it again.

 

Anyway, thanks for the help. If anyone knows how is the correct way to
update my microwindos folder without losing the changes for the
cross-compile, I'm open for ideas.

 

Rafael C. Schwarz

2008/12/18 Martin Kajdas ####@####.####

This is an old problem that was fixed with latest version (CVS).
Martin



-----Original Message-----
From: Rafael Schwarz ####@####.####
Sent: Thursday, December 18, 2008 5:27 AM
To: ####@####.####
Subject: [nanogui] PNG image with white pixels

Hi all,

I'm using FLTK 2.0, nxlib-0.45 and microwindows 0.91, and I'm having a
problem showing png images.
When the picture has a pixel totally white or almost white, it appears
black
on the screen.
I'm having a similar problem using nxview, but this time only the pixels
with the color totally white (R=255, G=255, B=255) appears black.
I've tried to debug it, but I can't find what is wrong.
Does anyone have the same problem? Any ideas for fixing it?

Thanks in advance,

Rafael C. Schwarz