The color space of the pixbuf.
Currently, only GDK_COLORSPACE_RGB is supported.
Whether the pixbuf has an alpha channel.
The number of rows of the pixbuf.
The number of samples per pixel.
Currently, only 3 or 4 samples per pixel are supported.
A pointer to the pixel data of the pixbuf.
The number of bytes between the start of a row and the start of the next row.
This number must (obviously) be at least as large as the width of the pixbuf.
The number of columns of the pixbuf.
The number of bits per sample.
Currently only 8 bit per sample are supported.