Align Layers/Composite Image/Change colours in product shot

[Rose NW]

What is the best way to use the first image (purple chair) as the source image and bring the blue upholstery in from the second image (so the chairs are perfectly aligned between images?

[Chuck Uebele · Accepted solution]

I would convert the blue chair image to L*A*B* color, make a selection of the parts you want changed, then use curves to change the color by setting an eyedropper on a diffused highlight and match the colors. You might have to invert the A or B channel to do so, but that's part of the magic of L*A*B*.

[Rose NW]

"change the color by setting an eyedropper on a diffused highlight and match the colors" - can you explain this in more detail?  Thank you!

[Chuck Uebele]

You want to sample the color in both chairs in a spot that isn't in the highlights nor the shadows, more in a mid range area, know as the diffused highlights. This gives you a more accurate color selection.

[davescm]

Hi

If you are just changing color then I would do as Chuck describes or select the upholstery and use a Hue and Sat adjustment layer set to colorize.

However if the patterning of the material is different then it will take a different approach using some transforming and warping. If this is the case can you attach the two actual images as the forum screenshots don't show sufficient detail.
To add the images as attachments, edit your original post by clicking More then Edit,  and below the posting box you will see a paper clip for adding attachments.

Dave

[Rose NW]

Great, thanks - the patterns are identical so it's just about changing the colour...

[Chuck Uebele]

Here's an example. I made a average swatch from the back of the chairs, as there was so much noise that might interfere. Even with that, matching the colors exactly per the info panel didn't look quite right, so I tweaked them a bit. but this is basically the setup in L*A*B* where you set two color sampling points and then adjust a curve layer to match the color. The blue chair is the bottom image.

[Rose NW]

Great, that's really helpful - thank you!  

[Lumigraphics]

If I'm changing color, I'll typically either do a rough change with Replace Color or select the area and desaturate, then switch to my new color. This makes it much easier to match final colors.