Name
Utilities -- Utility and miscellaneous convenience functions.
Synopsis
| 
#include <gdk-pixbuf/gdk-pixbuf.h>
GdkPixbuf*  gdk_pixbuf_add_alpha            (const GdkPixbuf *pixbuf,
                                             gboolean substitute_color,
                                             guchar r,
                                             guchar g,
                                             guchar b);
void        gdk_pixbuf_copy_area            (const GdkPixbuf *src_pixbuf,
                                             int src_x,
                                             int src_y,
                                             int width,
                                             int height,
                                             GdkPixbuf *dest_pixbuf,
                                             int dest_x,
                                             int dest_y);
void        gdk_pixbuf_saturate_and_pixelate
                                            (const GdkPixbuf *src,
                                             GdkPixbuf *dest,
                                             gfloat saturation,
                                             gboolean pixelate);
void        gdk_pixbuf_fill                 (GdkPixbuf *pixbuf,
                                             guint32 pixel); | 
Description
    These functions provide miscellaneous utilities for manipulating
    pixbufs.  The pixel data in pixbufs may of course be manipulated
    directly by applications, but several common operations can be
    performed by these functions instead.
  
Details
gdk_pixbuf_add_alpha ()
Takes an existing pixbuf and adds an alpha channel to it.
If the existing pixbuf already had an alpha channel, the channel
values are copied from the original; otherwise, the alpha channel
is initialized to 255 (full opacity).
If substitute_color is TRUE, then the color specified by (r, g, b) will be
assigned zero opacity. That is, if you pass (255, 255, 255) for the
substitute color, all white pixels will become fully transparent.
gdk_pixbuf_copy_area ()
| void        gdk_pixbuf_copy_area            (const GdkPixbuf *src_pixbuf,
                                             int src_x,
                                             int src_y,
                                             int width,
                                             int height,
                                             GdkPixbuf *dest_pixbuf,
                                             int dest_x,
                                             int dest_y); | 
Copies a rectangular area from src_pixbuf to dest_pixbuf.  Conversion of
pixbuf formats is done automatically.
gdk_pixbuf_saturate_and_pixelate ()
Modifies saturation and optionally pixelates src, placing the
result in dest. src and dest may be the same pixbuf with no ill
effects.  If saturation is 1.0 then saturation is not changed. If
it's less than 1.0, saturation is reduced (the image is darkened);
if greater than 1.0, saturation is increased (the image is
brightened). If pixelate is TRUE, then pixels are faded in a
checkerboard pattern to create a pixelated image. src and dest
must have the same image format, size, and rowstride.
gdk_pixbuf_fill ()
Clears a pixbuf to the given RGBA value, converting the RGBA value into
the pixbuf's pixel format. The alpha will be ignored if the pixbuf
doesn't have an alpha channel.