Imagemagick - top quality 85 does not function

I run mogrify to compress a JPEG photo to 85% top quality :

$ ls -lah Screenshot.jpg
-rw-rw-r--.  1 USER GROUP 440K May 24 12:10 Screenshot.jpg
$ mogrify -compress JPEG Screenshot.jpg -quality 85
$ ls -lah Screenshot.jpg
-rw-rw-r--.  1 USER GROUP 441K May 24 12:10 Screenshot.jpg

The dimension does not reduce. Yet if I open the photo in Gimp and also conserve at 85% top quality, the dimension does reduce :

ls -lah Screenshot.jpg
-rw-rw-r--.  1 USER GROUP 135K May 24 12:11 Screenshot.jpg

Why does not ImageMagick compress the JPEG photo to 85%? I'm making use of ImageMagick - 6.6.4.1 - 15. fc14.i686 on Fedora.

0
2019-12-02 03:09:13
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Answers: 1

It resembles the loved one getting of modifier debates (- top quality NN) and also filenames does issue below, virtually like it is doing what it is informed in a really, really simplified means.

: [email protected]; !ls
ls -lh Screenshot.jpg 
-rw-r--r--  1 cez  staff   1.3M  5 24 19:20 Screenshot.jpg
: [email protected]; mogrify -verbose -monitor -compress JPEG Screenshot.jpg -quality 10
load image[Screenshot.jpg]: 1079 of 1080, 100% complete
Screenshot.jpg JPEG 1920x1080 1920x1080+0+0 8-bit DirectClass 1.335MB 0.120u 0:05.680
save image[Screenshot.jpg]: 1079 of 1080, 100% complete
Screenshot.jpg JPEG 1920x1080 1920x1080+0+0 8-bit DirectClass 1.327MB 0.240u 0:02.960
: [email protected]; 

So, the very first time we run mogrify, we define the -quality argument after the filename, therefore it does not recognize that the top quality specifier need to relate to that photo.

: [email protected];mogrify -verbose -monitor -compress JPEG -quality 85 Screenshot.jpg 
load image[Screenshot.jpg]: 1079 of 1080, 100% complete
Screenshot.jpg JPEG 1920x1080 1920x1080+0+0 8-bit DirectClass 1.341MB 0.100u 0:00.119
save image[Screenshot.jpg]: 1079 of 1080, 100% complete
Screenshot.jpg JPEG 1920x1080 1920x1080+0+0 8-bit DirectClass 459KB 0.190u 0:00.200
: [email protected]; 

Conversely, if we define the top quality setup prior to the photo filename, it'll conserve the photo with even more compression, lowering the filesize.

0
2019-12-03 02:46:45
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