Output image not preserving CMYK color ratios and Blue lines misplaced

[Carter J]

Hi,

We are facing below two issues after resolution change from 72 to 300 for a JPEG-CMYK:

• 1. CMYK color ratio's of input file and output file differs
  2. Blue lines on input image are misplaced in output image (we can view the blue lines in both input image and output image only in Photoshop, below is comparision screenshot).
  https://www.dropbox.com/s/bulj08sb3ldlv ... t.jpg?dl=0

For Example: (Given below URL's for both input and output files)
For Input file
CMYK color ratio's at background of BT logo : 100,62,1,1

After conversion:
CMYK color ratio's at background of BT logo : 99,65,7,1

Could anyone suggest what could be the possible cause for above?

Command used:
convert -alpha off -layers merge -units pixelsperinch -resample 300 InputImage.jpg[0] -profile USWebCoatedSWOP.icc -profile USWebCoatedSWOP.icc outputImage.jpg

or

convert -units pixelsperinch -resample 300 InputImage.jpg[0] -profile USWebCoatedSWOP.icc -profile USWebCoatedSWOP.icc outputImage.jpg

input file:
https://www.dropbox.com/s/mpczhilffo1js ... e.jpg?dl=0

output file:
https://www.dropbox.com/s/jllzq3t0ky1we ... e.jpg?dl=0

[snibgo]

1. You are converting to another profile. This changes pixel values.

2. What blue lines?

[Carter J]

1. You are converting to another profile. This changes pixel values.
2. What blue lines?

Hi,

For both input and output image, we got same profile using below command.


1. You are converting to another profile. This changes pixel values

identify -format %[profile:icc] InputImage.jpg
U.S. Web Coated (SWOP) v2

identify -format %[profile:icc] outputImage.jpg
U.S. Web Coated (SWOP) v2

2. What blue lines?

We are able to view the blue lines in Photoshop only. I have modified the question and added comparison screenshot. Please verify

Thanks

[snibgo]

Sorry, I don't have Photoshop. Gimp and MS Photo Viewer show no blue lines. If they are vectors, IM will ignore them.

If you are not converting colorpaces, why do you have any "-profile" operations?

Your output is JPG. This is lossy, so it will change pixel values.

[Carter J]

Sorry, I don't have Photoshop. Gimp and MS Photo Viewer show no blue lines. If they are vectors, IM will ignore them.

If you are not converting colorpaces, why do you have any "-profile" operations?

Your output is JPG. This is lossy, so it will change pixel values.

If you are not converting colorpaces, why do you have any "-profile" operations?

For some images, profile is not retaining in output images. So, we are applying profiles irrespective of input image's profile.
Any problems with this approach?

Your output is JPG. This is lossy, so it will change pixel values.
We have done same thing, resampled image and applied color profiles thorough Photoshop and works fine without any issue

Any insight?