Noob question on PPing

Chr1stof

Chr1stof

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Chris
Edit My Images
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Just taking my first steps on the long path of PPing. I have just been playing around with some rather dull pictures and when I was done I found the file size had increased massively. Some have reached over 20mb having started at 6ish.
All I had done is mess with saturation, contrast and sharpness using Canon DPP.
I also have CS3 but not really used that yet, how can I reduce file size but maintain image quality?
Thanks
Chris
 
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Yes, shot and saved as jpg
 
That seems a big increase in file size, are you editing just the once or are you re-editing a few times? Also what are you doing just a basic edit or things like lens corrections?
Wayne
 
Sorry, dont what lens corrections are!
used DPP, altered saturation etc and clicked on convert and save. If I just use "save as", all DPP does is save the changes to the DPP library file. Convert and save still saves it as a jpg but as a massive file, no idea why
 
Chr1stof said:
Sorry, dont what lens corrections are!
used DPP, altered saturation etc and clicked on convert and save. If I just use "save as", all DPP does is save the changes to the DPP library file. Convert and save still saves it as a jpg but as a massive file, no idea why
Click to expand...

Lens correction will help fix things like distortion or colour fringing, but I don't know if it's in DPP anyway.
 
Seems a bit odd to me Chris the increase in file size. You sure you are not looking at the original Raw file again :shrug: as 20meg would seem about the right size for one. You can always load your jpeg into PS3 and then go to image > image size and then change it to 1024 on the longest side or whatever size you want, just apply a bit of extra sharpening before saving it normaly. Or as mentioned just use the save for web after setting the image to your desired size.
 
Just did an experiment. I used CS2 for this as I don't have DPP, but I think the basic principles will be the same.

Loaded a JPG into CS2. In the Windows file system, the JPG was 4.8 MB.

I told CS2 I was going to save the JPG, not having done anything to it. CS2 told me it would be 6.5 MB. This was using JPEG Quality 12 (the top quality) - as you reduce the quality the size goes down.

Changed the Saturation. CS2 said it would save as 6.8 MB.

Went back to the original. Changed the Contrast. CS2 said it would save as 7.3 MB.

Went back to the original. Sharpened it (a lot). CS2 said it would save as 8.9MB.

Went back to the original. Changed the Saturation and Contrast, and Sharpened (a lot). CS2 said it would save as 10.3 MB.

Sharpened it some more (it's getting silly by now, I can see sharpening artefacts). CS2 said it would save as 13.5 MB.

So, the size depends on what you have done to it, and also I imagine on the nature of image. For example, I think that a given amount of sharpening would increase the size more for an image with lots of detail than for one with very little detail.

The final size also depends on the JPEG Quality setting. Here are the sizes CS2 said the image would save as for the final version:

JPEG 12 - 13.5 MB
JPEG 11 - 8.1 MB
JPEG 10 - 5.4 MB
JPEG 9 - 4.2 MB
JPEG 8 - 3.5 MB
...
JPEG 0 - 0.5 MB
 
This one was silly size but after cropping went down to about 5mb-
5499940510_170ab3122c_z.jpg


This is still up at about 15meg!
5499906708_8ea09a222b_z.jpg
 
This one had saturation lowered right down (obviously!), contast/brightness up a bit and a bit of sharpening= 16meg from about 5meg

5499960542_6ab72aae33_z.jpg
 
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Chr1stof said:
This one had saturation lowered right down (obviously!), contast/brightness up a bit and a bit of sharpening= 16meg from about 5meg
Click to expand...

I forgot to mention, my SX10is has a 10 MPixel sensor. Assuming you are using a 550D, your camera's sensor has 18 MPixel. Scaling up my example by 18/10 to give a like for like comparison, my Saturation+Contrast+Sharpness example of 10.3 MB would scale up to about 18.5 MB, broadly similar to the sizes you are getting, so I suspect there is nothing particularly unusual about the sizes you are seeing (assuming you are saving with JPEG Quality 12).

You asked about reducing the size without losing quality.

You can reduce the size of your processed images quite a lot without losing much quality if you save with JPEG quality 10 or 9. That said, presumably you keep the original images? I hope so, the reason being that you may in due course want to have another go at post processing some of them. And that is best done starting again with the originals.

For posting on line, you need to get the size down to 200Kb or so (depending on the forum), so you will probably need to reduce the size to 1000 (ish) across for landscape images and save at JPEG 10 or so.
 
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When your saving out what's the dpi and resolution??

Could the program be saving at a large dpi say 300 or so? I can easily produce a 20 meg file when you start playing with the dpi
 
GardenersHelper said:
Just did an experiment. I used CS2 for this as I don't have DPP, but I think the basic principles will be the same.

Loaded a JPG into CS2. In the Windows file system, the JPG was 4.8 MB.

I told CS2 I was going to save the JPG, not having done anything to it. CS2 told me it would be 6.5 MB. This was using JPEG Quality 12 (the top quality) - as you reduce the quality the size goes down.

Changed the Saturation. CS2 said it would save as 6.8 MB.

Went back to the original. Changed the Contrast. CS2 said it would save as 7.3 MB.

Went back to the original. Sharpened it (a lot). CS2 said it would save as 8.9MB.

Went back to the original. Changed the Saturation and Contrast, and Sharpened (a lot). CS2 said it would save as 10.3 MB.

Sharpened it some more (it's getting silly by now, I can see sharpening artefacts). CS2 said it would save as 13.5 MB.

So, the size depends on what you have done to it, and also I imagine on the nature of image. For example, I think that a given amount of sharpening would increase the size more for an image with lots of detail than for one with very little detail.

The final size also depends on the JPEG Quality setting. Here are the sizes CS2 said the image would save as for the final version:

JPEG 12 - 13.5 MB
JPEG 11 - 8.1 MB
JPEG 10 - 5.4 MB
JPEG 9 - 4.2 MB
JPEG 8 - 3.5 MB
...
JPEG 0 - 0.5 MB
Click to expand...

Are I right in thinking your saving in between steps here? If so thats not a good way to work, although the jpeg is getting bigger file size wise, the recompression every time it's saved will reduce the quality and bring in jpeg artifacts eventually.
If the OP need to revist his image it would be better to save as a tiff for the in between stages and output as a jpeg at the end of the processing.
 
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zilly said:
When your saving out what's the dpi and resolution??

Could the program be saving at a large dpi say 300 or so? I can easily produce a 20 meg file when you start playing with the dpi
Click to expand...

Its on default which is 350 DPI and there is a tick in the box which says "embed ICC"
 
Chr1stof said:
Its on default which is 350 DPI and there is a tick in the box which says "embed ICC"
Click to expand...

That could be contributing to the file size. Try putting it down to 72 dpi and exporting another test
 
swanseamale47 said:
Are I right in thinking your saving in between steps here?
Click to expand...


No. I didn't save at all. After each of the operations I used File, Save As, and the dialogue box asked me what Quality to use, and indicated what the size would be for the Quality setting I selected. Having noted what the size would be I then cancelled the dialogue, and used PS History to take the image back to its as-opened state to repeat the process for the next operation.

swanseamale47 said:
If so thats not a good way to work, although the jpeg is getting bigger file size wise, the recompression every time it's saved will reduce the quality and bring in jpeg artifacts eventually.

If the OP need to revist his image it would be better to save as a tiff for the in between stages and output as a jpeg at the end of the processing.
Click to expand...

Although not relevant in this case, this is all certainly true and good for the OP to know about.

Mind you, having said that, from time to time I decide that a PP'd image (saved at JPEG 10) would benefit from a little tweak, and rather than redo from scratch with the original (which for some of my images can be a non-trivial exercise), I usually load the PP'd image, do the tweak and re-save as JPEG 10, which is quick and easy.

Being concerned about the issue of progressive quality loss with repeated saves, some time ago I did several very close comparisons of first-saved and second-saved versions, and as I recall I did not manage to convince myself that I could see any IQ loss. I believe there must have been some loss of IQ, but it was below my perceptual threshold.

I haven't done that sort of minute comparison since then, but I do always do a first-save versus second-save (and occasionally third-save) comparison to see which version I prefer, and sometimes this is a rather detailed comparison. Here too, I don't recall noticing any IQ loss. This may not apply generally though - I suspect that different types of image may react differently in terms of how easily they develop artefacts.

BTW, and FWIW, I use a comparison method that I believe is quite revealing of differences. I arrange it so that I can flick back and forth between versions with one version exactly replacing the other in terms of size and position. I keep my eyes fixed on a particular part of the image and watch how that area changes as I flick back and forth, for example by rocking the mouse wheel back and forth, which allows me to not take my eyes off the image. I find that differences between versions really jump out at me when I do this.
 
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