I am trying to learn the internals of image file formats and I wonder whether there is an application that could explain a file byte by byte.
I am thinking of something like Wireshark which actually has built-in suppport for PNGs. I especially like the UI of Wireshark, where data is grouped and can be expanded for more details and it highlights the raw bytes associated with the currently selected item (see screenshot below where the mouse hovers over "textual data").
The software should be gratis and for Windows. It should support all major images file formats: at least PNG, JPG, BMP, TIFF and GIF.
Ideally it would display the image, allow editing the bytes directly and update the preview immediately when changes are made.