addition to a byte for the red, green and blue colour components for each pixel
it also stores a byte representing the pixel opacity. The alpha value of $0$
corresponds to a transparent pixel (null opacity) while the value of $255$
addition to a byte for the red, green and blue colour components for each pixel
it also stores a byte representing the pixel opacity. The alpha value of $0$
corresponds to a transparent pixel (null opacity) while the value of $255$