need help with jpeg compression

[robertj298]

I just had to reinstall psp9 on a new computer running vista. My problem is even when I set the jpeg optimizer to its lowest setting the size of my jpeg file goes all the way from 4 megs to about 600kb just by making a minor change and saving. I don't believe any of my files were compressed this much before I reinstalled to vista...Bob

[robertj298]

I forgot to mention..I've even tried importing my photo as a tiff and doing corrections then saving as a jpeg and my jpegs are still compressed from 3 or 4 megs down to 600-700 kb....Bob

[handrawn]

Hi - welcome back

jpeg will always compress - whatever the setting - how much depends on the file content

its a 'lossy' format

[handrawn]

Ps - are you resizing them? - that might make a big difference...

[robertj298]

No resizing just a slight adjustment using a smudge brush. After importing the raw file into psp as a jpeg I have a 3 or 4 meg file but after a slight adjustment it compresses to 600-700 kb which seems a lot to me and even when I import the same photo as a tiff and do the adjustments when I save as a jpeg it still compresses just as much...Bob

[steve.ledger]

This is normal. As Steve said, JPEG is lossy compression.

For web use (where smaller files sizes are best) 75% quality setting is usual, 100% quality gives the least compression and larger files.

[robertj298]

What my point is I take a raw 11 meg photo file and export it as a 57 meg tiff file in psp and do a minor adjustment to the tiff file and save as the highest quality jpeg and I end up with an700 kb file which may be ok to post to the web but not if I want to print a large photo....Bob

[handrawn]

what's wrong with printing from a tif? - the tif format is intended to be printed from, jpeg never was..

[coningham]

When you say 4 Mb, is this what you see on PSP's status bar or on Windows Explorer?

[handrawn]

PS - if file size is an issue, you could try saving as .png - that compresses without loss and usually prints photos fine..