createBlankBitmap
Generates a BMP file of the given dimensions.
( string $image ) - The fully qualified path to the new file. If the file exists, it will be overwritten.
( int $width ) - Width of the BMP image, in pixels.
( int $height ) - Height of the BMP image, in pixels.
By default, the background is black. See comments in script to assign your own RGB color as the background.