Color issues using Irfanview

[tennessee]

I am using a great irfanview script to simply resize (and re-assign dpi) tons of images on a scheduler from the command line. Script works great.

I'm only now discovering there seems to be an issue with Irfanview itself, as the colors of the images are being shifted in a major way when simply resizing the photos. I have LCMS installed and enabled, but not sure what I need to do in order to keep the same color profile the original image had.

The ivew params in my script are:
/resize_long=2000
/dpi=(300,300)
/aspectratio
/jpgq=100

The image should "look" exactly the same as the original, simply reducing the size from 2200 pixels down to 200, and adjusting the dpi from 240 to 300. How can I keep the colors/vibrance untouched during the resize?

[tennessee]

Has no one every seen the color issues using iview? I can take an image and convert it to sRGB IE61966-2.1 in photoshop first (since that's what iview converts to), and then do my resizing in iview and the image still changes color going from sRGB IE61966-2.1 to sRGB IE61966-2.1

How can I retain my color...if anyone can help I would greatly appreciate it.

Also, if you have never seen this issue, I am also very interested in that...because it would seem hard to believe that this is not a widespread issue. Am I crazy, or does no one care that the images are being shifted in color in an unflattering way?

[Bhikkhu Pesala]

I missed your earlier post, and no one else has responded. You will have to wait for someone who knows more than I do. I am colour-blind and short-sighted, so I wouldn't notice unless the change was obvious.

Wouldn't you expect some change to the colours when resizing pictures? Where 121 pixels are changed to one, the new pixel would have to be a compromise, surely?

What is LCMS?

[tennessee]

LCMS is a plugin/addon for IrfanView...supposed to be for "color management". To answer your question, there is no change in the color when resizing in photoshop. Trust me, I've been experimenting at length to figure this out I'm talking about taking an image that is vibrant in color tone and noticeably desaturating it in the resulting file...even though the color space is identical before and after. This doesn't happen in Photoshop

[Gownaar]

My eyes may not be the most precise instruments but they can't detect this. Are you sure the color shift is due to resizing and not jpg saving? Because there's a noticeable aberration in red if you don't check 'Disable chroma color subsampling' in jpg options.

[tennessee]

I'm not seeing this option in Properties/Settings dialogue box. Where is that option located? See my attached jpg settings...

[Gownaar]

Not in preferences, in the dialog you get when saving.

[tennessee]

Hmm. Are those options something that I can get to by way of a script?

[Gownaar]

Not directly, only jpg quality. But settings will remembered and used in cmd mode as well. You can also create a separate copy of i_view32.ini and instruct IV to use it with /ini=; that way you'll protect your script output from being affected by subsequent settings changes you make in gui mode.