Combine many small obj files into one large obj file, and how to get the many small texture jpg files into one texture jpg file

Question

I have many small tile osgb files, I transform them into many obj files with texture jpg files. One obj file have own one texture jpg file.

Blender and Meshlab can combine many obj files into one large obj or ply files, but the texture jpg files can not be combine into one large texture jpg file. How can I solve it?