unsigned char * sod_image_to_blob(sod_img input);
Convert back a sod_img object to its original raw memory (i.e. Blob) representation.
1 to 3 bytes per pixel value of the original sod_img object is allocated & written into this memory pointer. if something goes wrong during processing (i.e. running out-of-memory), then NULL is returned instead. When done, sod_image_free_blob() must be called in order to avoid memory leaks.