[magick-users] Re: Re: Trouble converting 300dpi jpeg to 72dpi jpeg with same size

[Anthony Thyssen]

Nicolas Dhomont on  wrote...
| I'm using Imagemagick 6.2.4 10/02/2007 Q16 on linux
| 
| I used identify command as you did and I've understand a couple of things=
|  :
| 
| -- What I wanted is same geometry and lowered resolution.
| -- With identify, I checked images made with old process (using=20
| photoshop) and I noticed that 'hidef' images have both a higher=20
| resolution and geometry than 'lowdef' images. Finally, maybe lowered=20
| geometry and lowered resolution would be ok.
| -- Using density my 'outFile' has same geometry and same resolution than=20
| my 'fromFile'
| -- /Any way I use density, identify always shows me 'fromFile'=20
| resolution (maybe a bug, if someone wants my test logs, I can send him)/
| -- Using resample my 'outFile' has same geometry than my 'outFile' made=20
| with photoshop but resolution is still 300x300 and file size is also=20
| bigger than 'fromFile' file size. As the goal of my process is to obtain=20
| a lighter image, it's not usefull to me. With another message from=20
| Anthony I've understand why file size is bigger.
| 
| As density doesn't seem to work with me and I'm not sure to understand=20
| this (good) page : http://imagemagick.org/Usage/resize/#resample, I'll=20
| try to use jhead or exif editor as Anthony adviced me.
| 
If density is not working, you are probably using Photoshop.

Photoshop ignores tha normal default density setting of images except
for the density it saves in its own profile in the image.  You will need
to strip that profile to get photoshop to reconise the normal JPEG
density setting.


  Anthony Thyssen ( System Programmer )    <A.Thyssen at griffith.edu.au>
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