Don't use JPEG if you change the pic in any way

P

PhilipD

Well-known member
I found out that you should save all jpegs from camera to PNG before you re-size...Try it with one picture and put them side by side afterwards.
Also it's not just resizing...I only put text on a picture capture and the saved the original jpeg and the file went from 41kb to 11kb so it definitly makes the quality go down...you can even see the change...
let me know if that helps :)
 
Hello PhilipD, thanks for posting, the PNG vs JPEG has already been discussed somewhat here:

http://www.dvxuser.com/V6/showthread.php?t=138893&page=4

also note, that PNG (Portable Graphics Network) does not work very well with photos, it causes banding issues. PNG is best suited to graphcis/text etc that has lots of the same colors and are well defined.

The lossless and lossy attributes of both formats are well known, for video editing and compositing/VFX losseless codecs are the prefered way to go.
 
Thanks for the information, it helped a bit, should I stick to png at least for website making? I'll havea read of that thread :)
Anhar Miah said:
Hello PhilipD, thanks for posting, the PNG vs JPEG has already been discussed somewhat here:

http://www.dvxuser.com/V6/showthread.php?t=138893&page=4

also note, that PNG (Portable Graphics Network) does not work very well with photos, it causes banding issues. PNG is best suited to graphcis/text etc that has lots of the same colors and are well defined.

The lossless and lossy attributes of both formats are well known, for video editing and compositing/VFX losseless codecs are the prefered way to go.
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scratchpatchfilms said:
rejected!!!! off the backboard!!!! choked on the open net!!!!

sorry.
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if only I knew what that meant, but anyway I hope I've helped a few people as I always see people on the internet with pics that have been made a bit degraded but all it would have took was a save-as png :) , I can't remember how I found it out but I just did :)
 
Philip, I have been a full time fashion photographer in LA for a decade now. I started with the first available digital cameras. My current camera is the 1DsII. I shoot JPEG exclusively. It's a problem with your settings and your handling of the images. It's not a problem with the JPEG format.
 
When you shoot properly, there are no gains from shooting RAW. RAW will give you latitude for adjustment in post. When you dont need that latitude, it is unnecessary. Also, RAW files are 3 times the size of the JPG files, so when you are looking at having to triple archive between 500-1000 shots per day, that's alot of storage space. Finally, the compression settings on Canon's highest quality JPEGS is so slight there there are no artifacts. With every camera I have owned: Kodak DCS520, Nikon D1, Olympus E-10, Canon D30, 10D, 20D, 1DsII, 30D, I have done side by side 20x30 photographic prints of JPEG vs. RAW. There was no loss in quality in the JPEGs.
 
Now thats a pretty good point. So you're able to get your entire look in camera then is what you're saying. Not a bad deal at all I suppose. I shoot so wildly and am rarely in a controlled environment I rely pretty heavily on the RAW adjustments right now. I'm going to have to play with the camera some and see if Ican't get better at doing the adjustments in camera...
 
So you're able to get your entire look in camera then is what you're saying.
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No. But my exposure and white balance are always nailed. Those are the two adjustments in post that are hardest on image quality. I shoot super flat - no sharpening or saturation or contrast in the camera settings. Depending on what I'm shooting, and what it's for, I will usually only need a minor levels adjustment to bring the image where it needs to be.

BUT.... the JPEGs can handle ALOT of adjustment if you want to. The necessity of RAW is a myth. RAW is a nice option, but if your JPEGs are falling apart in post, look at your settings, look at handling in post, and most of all, fix your shooting technique.
 
Interesting. I've really never shot much jpeg and tried to process it as I thought RAW was infinitely superior. I didnt realize exposure and white balance were harder on image quality either. Now I'll have to start shooting jpegs and see what I can do. Sure would be nice to have all that space back. Thanks for the info Gage.
 
To be clear, RAW is superior, just not even close to "infinitely".

If you still need that post adjustment leeway, hang on to shooting RAW. I dont want you to lose images on my account. But also hear that I mentioned Canon's JPEG algorithms. I cant account for Nikon.

This is what works for me. I'm fine for everyone to keep doing what they're doing.
 
I only definitely wont be trying the jpegs out on anything paying. My stills are usually just a hobby thing for me right now. Actually now that I think about it I can shoot RAW+jpg at the same time. I suppose thats a pretty easy way to test the waters. I just would love to get the space back and stop having to process RAW files all of the time. While I love sticking with what works, sometimes I can't help but try new methods from time to time.
 
PhilipD said:
Thanks for the information, it helped a bit, should I stick to png at least for website making? I'll havea read of that thread :)
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Depends on what you file is, if you are saving graphics (eg logos, buttons etc) then PNG is great, if you are saving photos images then stick to JPEG for photos (it is optimised for this type of image)
 
GageFX said:
To be clear, RAW is superior, just not even close to "infinitely".

If you still need that post adjustment leeway, hang on to shooting RAW. I dont want you to lose images on my account. But also hear that I mentioned Canon's JPEG algorithms. I cant account for Nikon.

This is what works for me. I'm fine for everyone to keep doing what they're doing.
Click to expand...


Just to add, you can also save the JPEG as bitmap or TIFF and continue the post in the uncompressed format, no further generation loss will occur, but if you are editing jpegs and then saving in jpegs and then re-editing then thats a bad idea! :D
 
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All working files are saved as PSDs. I could never see a reason, other than blatant image abuse to take a jpeg, save it as a jpeg, then work on it again, then compress it again.

It's all PSDs for me.
 
With JPEG, if you have a high level of compression, it only take a few generations of un-compress/re-compress to generate compression artifacts. With a light level of compression, one can go through many generations before this problem pops up.

Even with low compression, if you zoom into an image, you can spot some of the 8x8 pixel block compression noise generated. In the upper image this is impossible to see, but with a zoom-in, we can see this. As compression is increased or we have multi-generations, this block noise gets worse.

Jpeg_Noise.png


This is just like compressed video, too much compression and too many generatioss can produce this block like effect.


Bob Diaz
 
I wouldnt classify that photo as a "low compression" image. There is no blocking at all on any of Canon's highest quality JPEGs. (10D an higher. I dont know about the Rebels.)
 
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