leche solara
Well-known member
Are you saving the change when you exit your editing program?
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Photo orientation
- Thread starter RangerD
- Start date
Guy Parsons
Forum Pro
F'rinstance, in Picasa when you wish to Export a file, you can choose the quality level from a few canned settings or Custom which allows a slider to be pushed up to 100 for best quality and largest file. Their default Custom setting is 85 so should be good enough for 99% of the time.
The image below shows the Picasa Export window with the Custom quality selected and the slider shoved across to 100.
What other programs do you use and we may be able to help where to find the quality settings if they aren't already obvious when you need to output a file.
Regards................ Guy
Guy,
Thanks for the detailed account on saving in Picassa. The screenshot helps me a lot as i'm a rather visual person (which is perhaps ironic
).
As for other programs I use: I primarily use Photoshop when making changes to photos...
RD
Thanks for the detailed account on saving in Picassa. The screenshot helps me a lot as i'm a rather visual person (which is perhaps ironic
).As for other programs I use: I primarily use Photoshop when making changes to photos...
RD
Seb
Leading Member
I've just tried similar test in Paint Shop Pro 8.
5 copies of the file:
1) original
2) 90° rotated once
2) 90° rotated twice
2) 90° rotated three times
2) 90° rotated four times
Sizes:
1) 2736KB
2) 2760KB
3) 2721KB
4) 2760KB
5) 2721KB
My guess is that the filesize variations come from 2 things:
Firstly the difference between 1) and 3) and 5) is due to the program changing the header data on the file in some way - there's lots of data in a JPEG that doesn't correspond to the file data itself - EXIF is just one example.
Secondly, the difference between 2/4 and 3/5 will be down to the orientation - one is an array of (say) 40 x 30 jpeg blocks, the other is (say) 30 x 40 jpeg blocks - due to some aspect of the algorithm used this results in slightly different sizes, with no difference in quality.
Indeed if I then load 1) and 5) into paint shop pro and do an "image subtraction" on them the resultant image is 100% black, proving that the quality has been totally unaffected throughout the rotations.
So, in other words - relax!
--
EOS 30D + 28-105 USM + 580EX
5 copies of the file:
1) original
2) 90° rotated once
2) 90° rotated twice
2) 90° rotated three times
2) 90° rotated four times
Sizes:
1) 2736KB
2) 2760KB
3) 2721KB
4) 2760KB
5) 2721KB
My guess is that the filesize variations come from 2 things:
Firstly the difference between 1) and 3) and 5) is due to the program changing the header data on the file in some way - there's lots of data in a JPEG that doesn't correspond to the file data itself - EXIF is just one example.
Secondly, the difference between 2/4 and 3/5 will be down to the orientation - one is an array of (say) 40 x 30 jpeg blocks, the other is (say) 30 x 40 jpeg blocks - due to some aspect of the algorithm used this results in slightly different sizes, with no difference in quality.
Indeed if I then load 1) and 5) into paint shop pro and do an "image subtraction" on them the resultant image is 100% black, proving that the quality has been totally unaffected throughout the rotations.
So, in other words - relax!
--
EOS 30D + 28-105 USM + 580EX
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