I generated an image patch database that contains 500,000 28×28 or 64×64 sized monochrome patches that were randomly sampled from 5000 representative natural images, including a mix of landscape, city, and indoor photos. I am offering them here for download from Dropbox. There are two files:
The first file contains 28×28 pixel patches and the second one contains 64×64 patches. The patches were sampled from a corpus of personal photographs at many different locations and uniformly in log scale. A concerted effort was made to avoid images with faces, so that these could be used as a non-face class for face detector training. However there are occasional faces that have slipped through but the frequency is less than one in one thousand.
The format of the files is very simple. It is just raw concatenated byte valued pixel data without any header, so for example for the 28×28 case there are 784 bytes for each image.
You can see 10,000 examples below:
If you find that the links don’t work, then try again the next day as Dropbox only gives me 20GB of bandwidth per day and these are large files.
I may expand this set to include color images, and I will update this page if I do.