Abstract: A video output checker (23) is described. The video output checker is configured to receive incoming video data (20) for rendering an image on a display (17). The video data comprises pixel data which comprise, for each pixel (42), a set of color component values (57, 57 2, 57 3) for a given color model. The video output checker can be configured to compare each color component for a pixel in a selected area (24) of the image with a corresponding test range of values (5 1L, 5 1U, 5 2L, 5 2U, 5 3L, 5 3U) and, if a component value falls outside the range, to measure a deviation. The video 10 output checker can be configured to sum deviations for the selected area to provide an error value (58) for the selected area, and to compare the error value against a threshold number (59).

Abstract: A video output checker (23) is described. The video output checker is configured to receive incoming video data (20) for rendering an image on a display (17). The video data comprises pixel data which comprise, for each pixel (42), a set of colour component values (57, 57 2, 57 3) for a given colour model. The video output checker can be configured to compare each colour component for a pixel in a selected area (24) of the image with a corresponding test range of values (5 1L, 5 1U, 5 2L, 5 2U, 5 3L, 5 3U) and, if a component value falls outside the range, to measure a deviation. The video 10 output checker can be configured to sum deviations for the selected area to provide an error value (58) for the selected area, and to compare the error value against a threshold number (59).