The imagem looks a little downscale, compare to PSX2PSP 1.4 Process

[felonyf0x]

very nice tool, now the games multi-tracks works perfectly, but i have a impression, when i do the conversion with that other programs, the game looks a little better, i say the image quality looks a little downscale with pop-fe... this could be a wrong impression about the image when i look, but i will try to post to Pictures Screen to compare... i was thinking, if this could be because a Pal Version looks a litte better or a NTSC, i realy don't know... i will test more and back here to tell more about it.

[Webardo]

Image quality should remain the same regardless of the converter used. Perhaps you are seeing a difference due to most PAL games having a higher resolution than NTSC games.

[sahlberg]

I don't think this is a pop-fe issue, as we don't modify anything on the disc image itself and (except for CDDA tracks) the disk image stored inside the EBOOT is 100% identical to the original disc image.

The difference you might see might be due to the different resolution between PAL and NTSC.
For some games the PAL version may have higher resolution than the NTSC version. This is likely what you are seeing.