Lossy jpeg

[DigPeter]

In vX1 I could save jpeg without substantialy reducing file Mb size. In vX4, whenever I edit and save a jpeg file (using save & save as), it results in a reduced number of Mb's. Options in the 'save as' dialog are set at best. It would appear that PSP X4 is automatically optimising. Is there any way that the original file size can be retained on saving after editing?

[Forriner]

In the "save as" dialogue, first select .jpg file type, then click on the 'options' button. Reduce the compression factor to as low as 1%. PSP uses 20% on installation. 'Save' uses the same compression factor as 'save as'.

[DigPeter]

Thanks - I have done this, but file size is still substantially reduced.

[Forriner]

Exif and ICC profile? Otherwise I'm stumped too.

[LeviFiction]

Well, usually JPEG loses pixels every time you save it. That's just what JPEG does, JPEG is lossy but you're right this doesn't explain what's going on with X4 and X5. The problem is the engine that was introduced in X4 does consistently result in smaller file sizes.

The claim by Corel is the new engine provides the same quality at a lower file-size. So yes the file-size is lower but you're not losing the quality that you gain by having a larger JPG. I can't say whether or not that's true but they are different. This was a big complaint from people who had been using PSP forever and suddenly their favorite JPG settings resulted in different outputs than they were used to.

There isn't much else to be done. So test the quality, see if it decreases along with the file-size. Maybe the fact that the file is getting smaller isn't a huge deal.

[LindaSue]

It probably depends on your image but I did a test and PSPX4's JPG came a out slightly larger file size than I got with PSP8; 236kb vs 229kb. PSPX2's JPG came out a whopping 367kb but also had the best quality of the three PSP versions (all using Standard encoding and a compression of 1). I purposely choose a colorful image with a lot of red in it, because red tends to "bleed" when compressed, and it also had lots of straight lines. PSP8 and X4 both added whitish "ghost" lines along all of the black outlines but X2 did not. X4's looks the worst to me and X2's the best.

[DigPeter]

Thanks for this interesting response.

The claim by Corel is the new engine provides the same quality at a lower file-size.

This is not supported by LindSue' test described below and does not accord with my experience!

There isn't much else to be done. So test the quality, see if it decreases along with the file-size. Maybe the fact that the file is getting smaller isn't a huge deal.

It is not a huge deal (few things in life are), because I keep the originals separate. But it is unsatisfactory. I use PSP mainly for removing unwanted objects, like power lines, but the final result is compromised.

Yes, I am a very long time user - my first version was, if I recall correctly, 3.

[DigPeter]

It probably depends on your image but I did a test and PSPX4's JPG came a out slightly larger file size than I got with PSP8; 236kb vs 229kb. PSPX2's JPG came out a whopping 367kb but also had the best quality of the three PSP versions (all using Standard encoding and a compression of 1). I purposely choose a colorful image with a lot of red in it, because red tends to "bleed" when compressed, and it also had lots of straight lines. PSP8 and X4 both added whitish "ghost" lines along all of the black outlines but X2 did not. X4's looks the worst to me and X2's the best.

Thanks for this, which confirms my subjective findings. I do not have X2, but X1 also gives an increased file size, and I think gives the best results.

OT: can anyone reading this please look at my post about loss of metadata at http://forum.corel.com/EN/viewtopic.php?f=56&t=48247 . Has anyone had the same experience? Handling of metadata in X1 was not perfect, but better than X4. I have looked for settings, but can find none that migth affect this.