Image Analysis & Accessibility

Reading images for quality and accessibility

Analysis tools can reveal properties that are easy to miss by eye, such as contrast, edge density, dominant colors, luminance, or other measurable characteristics. These results are most useful as diagnostics rather than automatic judgments about whether an image is good or bad.

For accessibility work, numerical checks should be paired with human review. A technically strong contrast score does not guarantee that text is readable, and image statistics cannot decide whether alternative text accurately communicates the purpose of an image in context.

Practical tips

• Use measurements to flag possible problems, then inspect the image yourself.
• Check text overlays at their actual display size, not only in a zoomed preview.
• Consider color-blind and low-vision users when color is carrying important meaning.
• Write alt text around the image’s purpose on the page rather than listing every visible object.
• Compare similar images using the same settings so the measurements remain meaningful.