A bitmap% object is a pixel-based image, either monochrome or color.
Sometimes, a bitmap object creation fails in a low-level manner. In that case, the ok? method returns #f, and the bitmap cannot be supplied to methods that consume or operate on bitmaps (otherwise, an exn:application:mismatch exception is raised).
Creates a monochrome bitmap from an array of bit values, where each character in bits specifies eight bits, and padding bits are added so that each bitmap line starts on a character boundary. A 1 bit value indicates black, and 0 indicates white. If width times height is larger than 8 times the length of bits, an exn:application:mismatch exception is raised.
Creates a new bitmap. If monochrome? is #f, the bitmap matches the display depth of the screen. The initial content of the bitmap is undefined.
Creates a bitmap from a file, where kind specifies the kind of image file. See load-file for details.