Half Life 2 Sheet.bmp

Where do I get the 357_sheet.bmp and the V_hand_sheet.bmp?

you can extract them yourself. grab gcfscape from http://nemesis.thewavelength.net/index.php?p=26 and look for source materials/gcf in steam/steamapps

And source doesn’t use bitmaps, it uses vtfs.

I have a VTF decompiler.

You don’t have to decompile them.

How do I get the .bmp if I don’t have to decompile them?
My importer use bmp for texture.

Use a photo editing software such as The GIMP or Paint.net they both have vtf plugins which you can download.

Or just use VTF Edit which is like 100 times easier…

VTF Edit can convert vtfs into image files?

Yeah, taking a file, converting it to something else, editing it, then converting it back is much easier than just opening the file, editing it and saving it. Get the vtf plugin for photoshop, using vtf edit or whatever else to convert the files is stupid and a waste of time.