This page has been redone, and now the explanation and solution have been added
ORIGINAL PROBLEM AND QUESTION
Why does file size gets larger when saved in Photoshop?
(I need help)
I use Photoshop 4.0 as my primary image editing software and have what appears to be a giant problem. Anytime I made any changes to an image in Photoshop I ended up with a much larger file size than I started with. I couldn't figure out why the most minute change made such a drastic increase in file size. Then I realized that the changes had nothing to do with the file size increase. Just saving the image in Photoshop dramatically increased file size. I don't know why!
The following photos and notations show the problem.
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Picture #1 This is the original scanned photo, 115 pixels wide and 156 pixels high. There are 72 pixels per inch. The file size is 4.57k. |
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Picture #2 This is Picture #1, opened in Photoshop 4.0 and saved under a new name. This picture was saved with medium compression, "JPEG Options" quality 4. The file size is 9.04k. |
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Picture #3 This is Picture #1, opened in ACDSee 3.1 and saved under a new name. There were no compression options presented in the "Save As" process. The file size is 4.49k. |
The following is a modified copy of an e-mail that I sent to a friend seeking his help. He does not have an answer, but the results described in the e-mail are another example of the problem I'm encountering:
I'd appreciate some help or advice with respect to Photoshop 4.0.
Everytime I do something to a .jpg in Photoshop the file becomes substantially larger than it was to start with. Not knowing why this was happening, as an experiment I opened four copies of a 43k jpg in Photoshop (not the photo shown above). Then, without making any changes to the images, I saved three of the copies using a different level of jpg compression for each. I saved one at minimum quality (level 0), one at medium quality (level 5), and one at maximum quality (level 10). These three jpg's made the following size files:
Original - 43k
Minimum - 37k
Medium - 64k
Maximum - 160k
It seems that I must be doing something wrong. I use the pictures I take to put on my website so file size is important. I almost can't use Photoshop because while I may improve the picture, the increased file size is not worth the improvement. There must be a way to edit photos in Photoshop without making the files larger.
Any help or suggestions would be greatly appreciated. Please e-mail me at argyle@stringbean.com
EXPLANATION AND SOLUTION
The problem is that Photoshop 4.0 has doing as it was intended to do, even though a file put into 4.0 and then saved becomes 50% larger (or even larger) than it was to start with. The reason for this is that prior to 5.0, it was the position of Adobe that Photoshop was not an application for manipulating images that were intended for posting on the web, etc., but only for images destined for hardcopy, albeit top quality, print. Therefore file size was not a factor. The increased file size comes from 4.0 taking information that it has gleamed from the image (hue, saturation, pixel settings, thumbnails, paths, and a zillion other such things) and incorporating this information as part of the file. Beginning with Photoshop 5.0 options began to appear that would enable you to save an image without all the non-image date.
Now, using Photoshop 5.5 and the "Save For Web" option, I again started with "Picture #1" from above and obtained the following results:
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Picture #4 This is the original scanned photo, 115 pixels wide and 156 pixels high. There are 72 pixels per inch. The file size is 4.57k. |
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Picture #5 This is Picture #1, opened in Photoshop 5.5 and saved under a new name. This picture was saved with medium compression, Quality 40 on scale of 100. The file size is 3.881k |
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Picture #6 This is Picture #1, opened in Photoshop 5.5 and saved under a new name. This picture was saved with high compression, Quality 12 on scale of 100. The file size is 2.329k, basically half the size of the original, but with noticable deterioration. |