I draw a bitmap image which has one colour, many pixels wide, all around the edge. This colour is set transparent (MakeTransparent()). When it appears on screen the other details are shown correctly, and most of the transparent area is shown
as such. However, there is a line one pixel wide on one or more edges, with a colour approximating the transparent colour. Seems to vary with the size of rendering. Maybe this is because the scaling algorithm is antialiasing at the edge and
producing a row of pixels which is not quite the transparent colour? How can I avoid this problem?Thanks