convert a Hex file to a PNG file, and compare the converted PNG files?

[Aaron]

Hello,

The %t parameter needs to be the entire file name, and can't handle a case where you need to add .png to it manually in the Conversion command line. If that is the case, you'd need a wrapper .bat or other script to handle that before passing it back and forth from BC4 to the helper app, and back. BC4 generates the .tmp file, and then also reads this file (which, would be entirely empty in this case since the converter utility is acting on tmp.png instead). From BC's perspective, the command line call of:
converter.exe %s %t
where %s is the source file, and %t is the converted output temp/target file, which then opens %t in the comparison pane.

[alum]

How can I use file format to add a Python tool to convert a Hex file to a PNG file, and compare the converted PNG files?
like ：
python test.py --path %s --output %t.png
and compare the png files
i tried，but it errors, said Conversion Error, without log