A New Method for Estimating the Widths of JPEG Images
  Image width is important for image understanding. We propose a novel method to estimate widths for JPEG images when their widths are not available. The key idea is that the distance between two decoded MCUs (Minimum Coded Unit) adjacent in the vertical direction is usually small, which is measured by the average Euclidean distance between the pixels from the bottom row of the top MCU and the top row of the bottom MCU. On PASCAL VOC 2010 challenge dataset and USC-SIPI image database, experimental results show the high performance of the proposed approach. 
Wu Xianyan, Han Qi, Le Dan, Niu Xiamu
cs.MM