A system and method for determining image quality by analyzing DCT information. Included is a system for measuring image quality of a compressed image divided into a plurality of blocks, wherein each block has frequency domain components including a DC coefficient value and a plurality of AC coefficient values, the system comprising: a module for analyzing the DC coefficient values from the plurality of blocks to quantify at least one image quality measurement selected from the group consisting of: average brightness, peak brightness, and contrast; and a module for analyzing the AC coefficient values from the plurality of blocks to quantify a focus measurement.