Enhancing the "dynamic range" of scanned images

الملخص EN

When digitizing images to computer normally the image is subject to some changes in the color tonal value, thus a post scanning process is a must to restore some of it's original color quality.

before the use of scanner a manual process is performed to give this action, with the use of digital software anew technique is need to give the same function enhancing the quality of the image color in the form of expanding the image dynamic range.

The problem of the present study is the scanning of images causes some loss in color data (in the form of shrinking the dynamic rage) this can be reviewed using the “ Histogram “ of the scanned image comparing with the dynamic range of the original print and measured using the info palette.

Some tonal correction operation that were carried out using the "photo-mechanical camera" are no longer been used, and therefore we lost this function when "photo-mechanical camera" is no longer been used that’s when we need to find a new digital function to replace that fatal tonal correction operation.

Therefore the target of this paper has been to convert the "photo-mechanical camera" tonal correction technique into a digital process by expanding the dynamic range of scanned image.