Bitmap to Jpeg back to Bitmap not equal
Posted on 1999-01-05
I am using Win98 and D4. In an attempt to conserve K space, I have converted my Bitmaps which are simple two color (gray and white) pictures to Jpegs. Later on a change of Jpegs back to Bitmaps the bitmap pictures appear to be the same but in fact they are not. As a test of accuracy I filled the original bitmap with a specific color. This produced an accurate fill.Later I did the same after I converted the jpeg to a bitmap. This revealed that the converted jpeg (now the bitmap) is,in fact, made up of many colors. All this is not easily seen except during an enlargement. Is there a programming sequence that will either maintain the accuracy when the original bitmap is converted into the Jpeg or later restore that accuracy when the Jpeg is converted back into a bitmap?