UMDGen

UMDGen is a compact and portable utility that enables you to create and edit PSP-supported ISO images in a user-friendly environment.
The main window is divided into multiple panels, dedicated to exploring directories, rerouting files, editing UMD properties, viewing sectors, and converting images in batch mode.
You can load an existing image or import files using either the file browser or drag-and-drop support. The file list shows the name, size, LBA and last date of modification for each item.
It is possible to assign a file as source and relink others to it, write master disc information and volume identification details, as well as optimize the image file by removing excess padding and resizing dummy data and "update" folder contents.
As far as image conversion goes, UMDGen supports the ISO, DAX and CSO formats for the output, and allows you to specify the compression value. In addition, you can use custom padding, associate PSP images with UMDGen, as well as disable program sounds.
The tool does not take a long while to carry out a task, and it uses very low CPU and RAM, so it doesn't decrease the overall performance of the system or interrupt user activity. We have not come across any issues throughout out evaluation, as UMDGen did not hang, crash or show error messages. All in all, this utility should please all users who want to create PSP-compliant ISO images.