As per my understanding, you want to read and convert a blocked image into png file format.
In MATLAB, you can do this using the 'images.blocked.PNGBlocks' adapter. It creates a 'PNGBlocks' object which reads and writes 2-D blocked image data in the PNG format.
If 'bim' is your blocked image, first write it to files using 'images.blocked.PNGBlocks' as the adapter.
wa = images.blocked.PNGBlocks();
write(bim, "dirOfPNGs", "Adapter", wa);
Here, 'dirOfPNGs' corresponds to the folder of images created. Next, to create a blocked image file having Blockformat as 'png', refer to the following command:
bpng = blockedImage("dirOfPNGs");
Hope it helps!
