pixbuf

A pixbuf, short for pixel buffer, is a data structure used to store image data in memory. In the GNOME project and its GTK toolkit, the term most often refers to the GdkPixbuf library, which provides a pixbuf type for loading, storing, and manipulating images.

A pixbuf encapsulates a rectangular array of pixels together with metadata. Typical fields include a pointer to the pixel data, the image width and height, a rowstride (the number of bytes between the start of one row and the next), and the number of color channels per pixel. Most pixbufs use 8 bits per sample and either 3 channels (RGB) or 4 channels (RGBA). A has_alpha flag indicates whether an alpha channel is present. Pixel data are stored in row-major order, with a specified channel order (commonly red, green, blue, [alpha]).

Pixbufs can be created from dimensions, from image files, or from memory buffers. They can be scaled, transformed, or converted between formats, and they can be drawn to different surfaces or widgets. In GTK applications, a pixbuf is often used with widgets such as GtkImage to display images, or passed to drawing routines and rendering pipelines like Cairo.

Memory management is handled through reference counting in the GObject system; pixbuf objects are shared and freed when no longer in use. See also GdkPixbuf and GTK for related libraries and concepts.