JPEG Quality VS Size

I'm in the process of cropping 5000 family pictures. They were all scanned on a flatbed with about 4 pictures per scan. I've realized that the cropped pictures are much larger in size than their original counterparts.

For example 45 of the original scans are 27MB in size, while those same pictures cropped (157 of them) are 156MB in size.

My action automatically saves the images at the maximum JPEG quality of 12. I'm wondering what the lowest i can lower the quality to is, while preserving the original scan quality of 300DPI?

Thanks!

L

jpg's wont save at 300dpi.... You'll need to save as a .tiff or something of that quality, so, layers and physical size will make for larger files. If you crop them to the size you need and no more, flattened, then you are about file saved as you can get at 300dpi.

marble,

i just looked at the image properties of both the original scans and the cropped versions that i've been saving at maximum JPEG quality.. photoshop tells me that they are both 300DPI.. how could this be off?

maybe this could help a bit?


http://de.uoregon.edu/help/changePS.html

http://www.layoutgalaxy.com/html/htmnewletter3-page3.htm

http://www.sprout.ie/tipzone_content.asp?ArtID=3

http://www.yourhtmlsource.com/images/fileformats.html

Sorry about the mislead, I was confusing myself. tiffs dont compress the images, but jpg's do, so if you want the best resolution use a tiff image. If you take a jpg image, like 60% and re save it again as a jpg at 100% it will grow in file size. That might be where you are having the problem. One solution would be to make a new action and save them at a lesser quality.
How big are the pictures?

Hrmmm. The cropped pictures are anywhere from 800kb - 900kb in size. When I go to specify the quality, I zoom into the picture and notice that any quality below 12 causes pixelization. I want to preserve these pictures in as high a quality as I can, even if they are JPEGS. How can I keep these at the quality they are, without making my project 4x bigger than what i started with?

Tiffs or photoshop format will be the only way to keep them without adding any compression. Tiffs are best because they will load into any graphics program. But I would probably save them as PS if I were planning on doing more work to them.

So how big are the pictures? Because 150mb seems kind of large for one photo. Maybe make them smaller? Are you thinking of keeping them so you can print them later?

If I was saving off large amounts of family photos and didn't want any compression, I would save as PNG format. PNG is lossless and compresses somewhat, certainly better file sizes than TIFF and BMP can give you.

JPEG compression on a large 300ppi image should be fine. I would save at 80% quality. JPEG Artifacting on large images isn't as noticable as it is on smaller, web-size images.

Try this trick...

Save you image as psd (the acrobat format), when you get the compression dialog choose Zip ratrher than jpg.

You will get a compression similar to the one of jpg in file size, but you will not lost image quality!!!!

You can save tham as Tiff or eps, than use winzip to compress tham with out losing quality. You can also group many of them in one .zip so group related photos wixh also help to manage them!