Approaches to resize an uploaded image of unknown format with Python

PIL is great for resizing an image 99% of time. But as there are some formats which PIL cannot handle, e.g. interlaced PNG images, I wonder is there any other libraries to work with as a supplement to PIL when we encounter a unsupported image.

Besides interlaced PNG images, what other formats are not currently supported by PIL? As users may upload whatever images they have, how do we pass those images unrecognized by PIL to correct third party libraries to convert to standard format?

Making system call to ImageMagick's convert command may do the job but it's not convenient to get original image's dimensions before conversion.

You can use the binding python of imagemagick maybe : MagickWand You might also be interested in PythonMagickWand