-------- Original Message --------
On 06/27/2012 04:26 PM, Kjell Ahlstedt wrote:
2012-06-26 11:44, Kees Kling skrev:
Hi,
I have created a pix_buf from 8 bits data with the function
create_from_data (const guint8* data, Colorspace colorspace, bool has_alpha, int
bits_per_sample, int width, int height, int rowstride).
It displays fine, but only in greyscale, so I must attach a
colortable, which maps a 8 bits value to an RGB color and
preferable to an RGBA color. What the best way to do this, I
can't find much documentation.
Regards
Kees Kling
The documentation of the C module gdk-pixbuf is located at http://developer.gnome.org/gdk-pixbuf/stable/.
Perhaps you can find some information there, e.g. in "The
GdkPixbuf Structure" section at
http://developer.gnome.org/gdk-pixbuf/stable/gdk-pixbuf-The-GdkPixbuf-Structure.html.
When I look at that documentation and a small part of the
gdk-pixbuf source code, I get the impression that each pixel is
represented by 3 or 4 bytes, called either channels or samples:
one byte each for red, green, blue, and an optional byte for an
alpha channel. But if that's the whole truth, I don't understand
why you get only greyscale pictures.
Kjell
Hi Kjell,
my data is just one byte and I want to display it as a color image.
So for that I'm going to use a colortable with 255 entrys and in
fact I have to translate every byte value in 3 or 4 bytes found in
the colortable. It is nothing new, because I think bmp format does
the same. Off coarse it is possible to do just a one by one pixel
translation, but my data could be rather big, so there is a time
and mem penalty. I should like to know if there is a better way
Regards
Kees
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