Test images are sample pictures used to evaluate the performance of various imaging systems, such as cameras, printers, and displays. These images often contain a range of colors, patterns, and textures to help assess how well the device reproduces details, contrast, and color accuracy. In many cases, test images are standardized, meaning they are widely recognized and used across the industry. Examples include the ISO 12233 chart for resolution testing and the ColorChecker for color accuracy. By analyzing the results from these test images, manufacturers and users can determine the quality and capabilities of their imaging equipment.