Re: Image procesin in gtk

[Dov Grobgeld <dov imagic weizmann ac il>]

Hi Amit,

You first need to read the image into a pixbuf e.g. by doing:

   GdkPixbuf *pixbuf;
   GError *error = NULL;

   pixbuf = gdk_pixbuf_read(filename,
                         &error);

You may now access the pixel data as follows:

   int row_stride = gdk_pixbuf_get_rowstride(pixbuf);
   guchar* pixels = gdk_pixbuf_get_pixels(pixbuf);

   /* Get r,g, b values at position col_idx, row_idx */

   guchar gl_r = pixels[(row_stride * row_idx + col_idx)*3];
   guchar gl_g = pixels[(row_stride * row_idx + col_idx)*3+1];
   guchar gl_b = pixels[(row_stride * row_idx + col_idx)*3+2];

There are are a couple things that you should note:

   * Pixbufs are currently always 24 bits per pixel (sample).
   * Gray images are loaded with each 8-bit gray level repeated
     three times.

For further info see the gdk-pixbuf documentation at:

    http://developer.gnome.org/doc/API/2.0/gdk-pixbuf/index.html

Regards,
Dov

On Wed, Jun 19, 2002 at 05:23:27PM -0000, amit  chawre wrote:
> 
> Hi,
> 
>      I am doing a project in image procesing.
> for that i need to read a image pixel by pixel.
> 
> Is there any way to read graylevel or color of
> specified pixel from a given image in picturebox?
> 
> Just like picture1.point(i,j) method in VB.
> 
> Any ideas?
> 
> Regard,
> 
> Amit Chawre
> 
> IIIrd year
> CSE IIT-Guwahati
> INDIA.
> 
> _________________________________________________________
> There is always a better job for you at Monsterindia.com.
> Go now http://monsterindia.com/rediffin/
> 
> _______________________________________________
> gtk-list mailing list
> gtk-list gnome org
> http://mail.gnome.org/mailman/listinfo/gtk-list

-- 
                                                        ___   ___
                                                      /  o  \   o \
Dov Grobgeld                                         ( o  o  ) o   |
The Weizmann Institute of Science, Israel             \  o  /o  o /
"Where the tree of wisdom carries oranges"              | |   | |
                                                       _| |_ _| |_