Test image

Image used in a test, captcha or image used as a test in a quiz or game.

Example: a series of images shows a detail from a famous painting; you have to recognise the title and the painter of each painting. In this situation, it is not possible to give a relevant alternative (for example the name of the painting and/or the painter) without rendering the test unusable. In this case, the alternative must simply give the possibility of identifying the image, for example "test image 1".