JPG size change problem - batch processing

[lionel]

My Canon 7D typically produces a JPG file in the 5B to 12MB range if set to the largest JPG quality. My problem is that if I open for example a 7MB file in Photo Pro X3 and save it again (even if I make no changes) the resulting file is about 2MB. Obviously some compression is happening which I want to avoid/control. Is it possible to set the default compression that X3 uses?
If I use file - export - JPG optimiser I can control things but that is not going to help me if I for example want to do a batch process on lots of files.
I have used Paintshop Pro since version 5 and love it but I might have to change to another editor if I cannot solve this one.
Lionel

[LeviFiction]

In the SaveAs dialog you'll see a button at the bottom that says "Options" click this to set the various options for the file-format you're trying to save in.

Export and SaveAs have the same options but they actually preserve their results for themselves so Export will have different settings than Save As but once you set it in Save As you should be fine for batch scripting and the like.

[teknisyan]

Here's another solution that you can follow if you're working with the 7D RAW files, you can perform this 000011162 - How to keep the high-quality of image from RAW Files to another file format? or this second KB 000011107 - How to save a Jpeg (*.jpg) and keep the high-quality of the photo?

[lionel]

Thanks for the input Levifiction but it does not work.
Yes it does remember last save compression options if you just open then save or save as that one file. However, if you do a batch process it does not use those last saved settings. It seems to revert to some other default, compression factor 20 in Photo Pro X3.
Testing in my old PSP 8 gives the same result except that it seems to use a different scale for compression and defaults to a factor of 15.
The process I carried out was just a simple mirror, so that should not have affected file size in any way.

This is a pain because I cannot batch process any images direct from camera without reducing quality.

[lionel]

Here's another solution that you can follow if you're working with the 7D RAW files, you can perform this 000011162 - How to keep the high-quality of image from RAW Files to another file format? or this second KB 000011107 - How to save a Jpeg (*.jpg) and keep the high-quality of the photo?

To date I have not used RAW significantly at all. Until I get a new computer with lots more storage I am not likely to go that way. RAW or lossless JPG are going to be about 3 times the size of the best quality JPG that comes off the camera.

The second link you referred doesn't work quite like the link states. With my X3 it is not possible to set a compression factor of 0, 1 is the lowest. If I set it to 1 a file that came off the camera at about 8.5MB ends up as 15MB. A compressio'n factor of 4 gives a file size just slightly larger than the original which would be satisfactory. It seems that X3 interprets the JPG it opens to generate all of the individual pixels and if you choose not to compress it saves info for all pixels, even the ones generated from compressed data.

It also does not address the problem with batch files as I mentioned in the reply to LeviFiction. I guess the question to be answered is "where does the batch process get its compression defaults from and how can I change them?" Quite clearly it does not take those values from what the user sets in his last Save As options

[LeviFiction]

Okay, in my batch processes dialog, and I haven't looked at it in ages so I'm sorry I missed something so obvious, but right next to the "Type" drop-down box is its own "Options" button that you can press and edit the settings of. Obviously the save type has to be "Save New" and not "Copy" or "Overwrite." But that should do well for batches.

[lionel]

Okay, in my batch processes dialog, and I haven't looked at it in ages so I'm sorry I missed something so obvious, but right next to the "Type" drop-down box is its own "Options" button that you can press and edit the settings of. Obviously the save type has to be "Save New" and not "Copy" or "Overwrite." But that should do well for batches.

You are a champion Levi, no fiction
The number of years I have taught kids in IT and answered their questions with "read the screen" or "read the dialog box"!
It is interesting that the compression factors set here give different file sizes from those in the option boxes we have checked out previously. A file of about 9MB goes to 10.5 MB at compression 1 ant to 7.5MB using compression 2. Good enough I suppose.

[lionel]

Here's another solution that you can follow if you're working with the 7D RAW files, you can perform this 000011162 - How to keep the high-quality of image from RAW Files to another file format? or this second KB 000011107 - How to save a Jpeg (*.jpg) and keep the high-quality of the photo?

To date I have not used RAW significantly at all. Until I get a new computer with lots more storage I am not likely to go that way. RAW or lossless JPG are going to be about 3 times the size of the best quality JPG that comes off the camera.

The second link you referred doesn't work quite like the link states. With my X3 it is not possible to set a compression factor of 0, 1 is the lowest. If I set it to 1 a file that came off the camera at about 8.5MB ends up as 15MB. A compressio'n factor of 4 gives a file size just slightly larger than the original which would be satisfactory. It seems that X3 interprets the JPG it opens to generate all of the individual pixels and if you choose not to compress it saves info for all pixels, even the ones generated from compressed data.

It also does not address the problem with batch files as I mentioned in the reply to LeviFiction. I guess the question to be answered is "where does the batch process get its compression defaults from and how can I change them?" Quite clearly it does not take those values from what the user sets in his last Save As options

Last note from me Abiel, LeviFiction helped me to a useful solution but I did play around with saving in JPG lossless format. The files produces could not be read by four out of five other image applications I tried. They said the files were corrupted. The one that did open them, Canon Zoom Browser, displayed the yellows as blue. Interesting looking hawk but I guess the file was corrupt. The only apps to open them successfully were PSP8 and PSPPX3. Not a very good or useful situation.