Using the GWX Terrain Extractor, SH4 tiles are 601x601 when opened in PS for the first time, and the tiles do overlap by 6 pixels also. If you do NOT get the transitions between tiles edited exactly correct, you often end up with pillars of rock six pixels wide and hundreds of ?? pixels high at the corner junctions. You also have to do all edits in one session. You cannot go back in and re-edit any mistakes you make, else you might end up with 6 pixel wide walls or trenches at the borders, depending upon your edits. Therefore, it's best to print out the original tile on paper, and noodle with that and a pencil first, then use the software. There is an issue with either the PS edits, the Save back to RAW, or the conversion from RAW to the game's ZHF, and you end up with the blank dimensions in the Open dialog if trying to edit a 2nd time. If you just do one edit on the RAW file, then it will display in the game correctly after a single edit session with PS, else you get that shift of six pixels, and other areas near the 6 pixle "border" area that have changed their values. Anymore, if editing terrain for SH4, I export to RAW each time I do an edit, instead of trying to re-edit. Very frustrating...
Edit: oooohhh, as I was typing Jeff posts about those first four bytes... I will be doing some experiments with that in a few days! I could try that 010 script for you Jeff!... thank you! :salute