Increasing contrast and sharpening moderately with the PhotoShop unsharp mask darkens Cassini's division a little and improves the contrast of the cloud tops but further hides the Crepe ring except in front of the planet. . Increasing brightness until the Crepe ring can be seen against the sky washes out the cloud tops on the planet, lightens Cassini's division and produces a gray rather than black sky. . . The following is a step by step 'how to' make and use a custom unsharp mask with Adobe PhotoShop. The original image is now darker but some obvious change has occurred. . The suggested adjustments are just that, suggestions.
Experimentation is the key.
Thierry Legault and Antonio Cidadao both offer useful information on image processing of planetary images. Jerry Lodriguss has an excellent collection of articles on CCD imaging, one of which clearly explains the use of unsharp masks for improving the dynamic range in images of deep sky objects and is obviously applicable to planetary images. . . Gordon Garcia used a custom unsharp on a H-alpha solar image. The unprocessed image above has been cropped, resized and saved as a JPEG, but no unsharp masking, histogram adjustment, etc. . . . . I adjusted the histogram of the original image before the mask was applied and after.