In most scenarios, cpt to jpeg conversion is an attempt to convert Corel Photo-Paint pictures (.cpt) to JPEG format. It appears that .cpt images can be simply re-saved as .jpeg or .jpg files in Corel PhotoPaint itself, or some graphics editor or convertor that supports CPT format.
Note: One program for Windows Mobile called Pocket Slides used .cpt files for presentations and these could have also been exported as JPEG images with the app, but that's something very old.Open CPT file Open JPEG file
A photo editing software distributed as a part of CorelDRAW
A multimedia presentation creator for Windows Mobile
A dedicated conversion software
A popular utility for viewing and converting graphic files