JPGs from GIMP are smaller than from ImageMagick

[ITdreamer]

Hi

I have an image from my photo. It is 2256x1496 in size.
1) I opened it in GIMP resized to 1000x663 and saved to JPG with 80% quality (all other saving settings were GIMP's defaults). And I got a good image, which is 69Kbytes in size.

2) I did the same with "convert pic.jpg -resize 1000 -quality 80 -type optimize pic_new.jpg"
And I got an image, which is 133Kbytes in size.

Can someone help me understand why it is so?

I have got 100 images, and I want to convert them to the size of 1000x663 with a good quality and the smallest possible weight and download them to server. And I don't want to do it in GIMP one by one. But the weight of the image from GIMP is about 2 times less than from the imagemagick.

What is wrong? Please, help.

[fmw42]

Are you using Q16 or Q8 IM? If Q16, then try adding -depth 8 to your IM command line.

[el_supremo]

The original image probably has metadata such as EXIF information or a colour profile.
Try adding the -strip option to have IM remove the metadata:

Code: Select all

convert pic.jpg -strip -resize 1000 -quality 80 -type optimize pic_new.jpg

Pete