What defines low contrast in an image?

Low contrast in an image is characterized by a short gray-scale with only a few shades of gray. This limited range means that there is less differentiation between the different tones, leading to a flat or dull appearance in the image. Such a lack of variety in gray shades can make it challenging to distinguish between structures or details within the image, as the subtle differences that might indicate various features are less pronounced.

In contrast, a long gray-scale with many shades of gray would indicate high contrast. High contrast images allow for greater distinction between different areas and features, enhancing visibility and detail. High gray-scale brightness typically contributes to an image being bright and could indicate areas where contrast might be lower if there is lack of differentiation in shades. Lastly, an image with no shades of gray would result in a binary or monochrome effect, but it doesn’t encompass the idea of low contrast, which is specifically related to the scarcity of varying shades rather than the absence of them.