Graphic Workshop's View mode includes a rich library of image processing filters which can be interactively applied to graphics to improve their appearance. You may find them helpful in adjusting marginal images to make it more apparent what they depict; to resize or transform graphics for presentation and to improve the clarity of pictures which have been deliberately degraded to make it less obvious what they contain.
Not all the filters in the Graphic Workshop filter library will be of use in forensic applications. Some of them are special effects, for other applications.
Here are a few of the filter functions you might find useful in forensic applications:
Color and Intensity: Adjust the color balance and brightness of an image to correct for intentional or accidental color shifts, or poor exposure settings.
Contrast and Brightness: Adjust the contrast and brightness of an image to correct for poor exposure settings.
Equalize: Redistribute the highlights and shadows of an image to make it easier to see.
Flip: Flip an image horizontally or vertically.
Gaussian Blur: Not all that helpful by itself, blurring an image can be useful in reducing moiré patterns. When a mechanically-screened image -- such as a photograph printed in a book or a magazine - is reproduced with a digital scanner, the image can be overlaid with a regular interference pattern, or "moiré." It's typically impossible to remove a moiré entirely once it's been created, but you can usually reduce its effect, and make the underlying image more readable, by first blurring the image slightly with the Gaussian Blur filter, and then using the Sharpen filter to un-blur it. Plan to experiment to get a feel for how to use this technique.
Hue Saturation and Brightness: This is an alternate color model for adjusting the color of images. You might find it more intuitive than the Color and Intensity filter.
Invert Colors: This filter turns images into negatives. More to the point, it turns images that have been deliberately turned into negative to make them less easily identified back into positives.
Normalize: This filter will increase the contrast of an image as much as possible, to make it as viewable as possible. It's a quick way to enhance washed-out or poorly exposed pictures.
Resize: This filter will resize your graphics - it's helpful if you're creating graphics for a printed document or a PowerPoint presentation, for example.
Rotate: This filter will rotate your graphics by any amount, adjustable to one degree.
White Balance: This filter will locate the lightest pixel in an image and adjust color of the entire image by the amount needed to make the lightest pixel pure white. It's a quick way to improve badly exposed pictures.
There are a great many other filters available in the Graphic Workshop filter library. The Reference document lists them all.