How can I perfom a regression (in the machine learning context) on images? - MATLAB Answers - MATLAB Central

By regression, I mean the derivation of a continuous property of an image (e.g. the mean area of the objects shown on the image) from its pixeldata. I'd like to train the algorithm with several images with known properties, in order to use it to analyze unknown images. From my limited understanding, this should be possible. Nevertheless, I only found examples of image classification or regressions of numerical values. Therefore, I'd be very thankful for hints to examples or tutorials.