Thanks to Bob Spelten, an update of the BMP graphics converter is now available from the Graphics page on my website.
Version 1.04 fixes a problem with conversion of Mode 33 images on Q68 (and probably Q40/Q60 too), which could result in incorrect colour conversion due to incorrect interpretation of the I bit.. The Files menu could go wrong when there was only one executable or relocatable file in a directory in the previous version. And the default pixel sizes of the Mode/Size menu defaults to 0 for X and Y, which could cause problems if not manually changed, so now defaults to 512×256.
Download the v1.04 update from http://www.dilwyn.me.uk/graphics/index.html