Trouble w/ Photoshop

[Anonymous]

Thanks alot guys, that information really helped. While I'm not sure why my computer was running so slowly (its a iMac G4, 1.2G processor and 10 G of hard drive space), I decided to use the state of the art computers in the College of Fine Arts to do my work and it went great.

BTW, I love your work at Rockville dsktc. I'm down the line in Pittsburgh so I see the same trains you do +/- five hours.

[eastside]

QUOTE: Originally posted by stmtrolleyguy

So in other words, Photoshop can compress the Tiff into a Jepg, for export, web use, etc., but when it's re-opened, it will revert back to full-size and resolution for further editing?

Not quite. Photoshop reads an image and converts it into an internal format that it can work on. That means that every pixel is expressed. A 100 kb JPEG may be expanded to 2 mb internally. An uncompressed TIFF would transfer pixels one-for-one. The user may then write it out as a JPEG, which uses an algorithm to compress the file size. Thus the uncompressed TIFF file may be 2 mb and the JPEG version may be as small as 100 kb. The trade-off is that with each generation of JPEG you lose information because of the compression algorithm. At first, the loss is hardly noticeable. Eventually, the loss compounds so that the image is noticeably degraded. JPEGs are also called a "lossey" format. Photoshop's own PSD format compresses without loss, but without the dramatic savings available with JPEG. Photoshop tells you the size of the uncompressed image in the image resize menu, but that doesn't say what the file size will be.

[Anonymous]

QUOTE: Originally posted by stmtrolleyguy

So in other words, Photoshop can compress the Tiff into a Jepg, for export, web use, etc., but when it's re-opened, it will revert back to full-size and resolution for further editing?

I've never really looked that closely (my digital camera isn't high enough resolution to resize most of my stuff, and I've never noticed.)

No, I don't think that is at all what he meant.

I think what he meant is that when you go back to open the pictures you made, you are finding the original TIFF files, and not the JPG.

Do the files you are opening which say they are 55MB,have a file extension of TIF or JPG?

Try this just for chuckles:

Make a dedicated directory for the finished product.

Call it JPEGS.

when you convert the file to a *.jpg make sure you "save as" a *.JPG into the JPEGS directory, and that when you go to open them up, make sure you are IN the JPEGS directory

If that doesn't help, I've seen a bug where converting freshly scanned images to a JPG format sometimes does not compress correctly. Which can be worked around if you save the tiff first to a *.BMP format, then convert the *.BMP to *.JPG..

try both suggestions, and see if either solves your problem

[stmtrolleyguy]

So in other words, Photoshop can compress the Tiff into a Jepg, for export, web use, etc., but when it's re-opened, it will revert back to full-size and resolution for further editing?

I've never really looked that closely (my digital camera isn't high enough resolution to resize most of my stuff, and I've never noticed.)

[eastside]

QUOTE: Originally posted by jdirelan

Quick question to fellow Rail photographer;
I recently scanned some slides on to my computer and was sharpening them with Photoshop CS. Then I saved them as JPEGs (I scanned them as TIFFs) at around 1 MB in size (The TIFFs where about 55 MB).
According to the information in my finder, the photos are 1 MB but when I reopen them with Photoshop, they're still 55 MB, too big for computer to handle correctly.

How can I decrease the size of these files once and for all?

You should mention also the version of Photoshop, OS, and amount of RAM you have. If you save a TIFF as a JPEG there will be compression, but once you read the JPEG back for manipulation it has to be uncompressed back to 55mb so that PS can work with the image. Incidentally, a 55mb image isn't a very large image for Photoshop. For example, I regularly work with 350mb images on my PC.

The PC you're using must have a very limited amount of memory. I'd say that if you're a regular user of PS you should have 1.5gb at minimum. There is a good reason to work off the original TIFF files because JPEG is what called a lossey storage method. That is the act of compression degrades the image slightly even if you do nothing. After several sessions this degradation will probably become noticeable.

[Anonymous]

You must have opened the TIFFs
by mistake.

Delete the TIFFs if you no longer
need them.

The JPEGs, as you discovered,
are much smaller in file size,
and therefore use less memory
and space.

Dave
http://www.railpictures.net/showphotos.php?userid=920

[Anonymous]

Quick question to fellow Rail photographer;
I recently scanned some slides on to my computer and was sharpening them with Photoshop CS. Then I saved them as JPEGs (I scanned them as TIFFs) at around 1 MB in size (The TIFFs where about 55 MB).
According to the information in my finder, the photos are 1 MB but when I reopen them with Photoshop, they're still 55 MB, too big for computer to handle correctly.

How can I decrease the size of these files once and for all?