Replacing Background Image with Higher Quality Version of same Image

[philips22399292]

Hi everyone,

I scanned several photos for printing at 30 x 45 cm. I opening them in photoshop and reworked them quite a bit, turning them partially into illustrations, which was time consuming.

After doing test prints, I realised they would work much better at a larger print size, which means I have to rescan them. I was trying to avoid larger scans because they are expensive. 

My question is: Is it possible to replace a Background Image in a Photoshop project with the same Background Image but scanned at a higher quality? I don't want to start the illustration and retouch process over from scratch with the higher quality scans.

Thanks for reading!

< J.R.

[c.pfaffenbichler]

One could replace a Start Object with a version of higher resolution but the probability that the scans have the exact same cropping, rotation, size etc. seems negligible.

Als you mentioned »retouch« I suspect the question is moot anyway.

For »Illustration« have you used Shape Layers and Vector Masks?

Have you tried upsampling with the (relatively new) Resample options »Preserve Details« and »Preserve Details 2.0«?

[Chad Chelius]

Hi J.R.

The answer to your question is not straightforward unfortunately. Technically yes you can replace one image with another that is of higher quality. You can do this a couple different ways. One would be manually. The other would be a method I prefer which is to use a Smart Object and then you can choose Replace Contents on the Smart Object and choose another image to replace it. That being said, if your new image is a higher resolution and larger dimensions, it might get cropped.

Beyond that, I think you're asking if there's a way to replace an image that you've done manual work to with a newer higher resolution image that you rescanned. The answer is no. All of that work that you performed on that original image can't be translated to the newer high-res image. I'm sure you already know this, but you always want to make sure that your resolution requirements are sufficient prior to doing extensive work on that file to avoid the situation that you're in.

I might suggest you check out a 3rd part plug-in such as Perfect Resize by On1 software (Perfect Resize 9.5 – ON1) that does a really good job of enlarging and increasing the resolution of an image. You may be able to resize the image that you've already done work to in order to make it work. Just a suggestion.

I hope that helps!

[davescm · Accepted solution]

To add to the answers above, it also depends on whether you did all of the retouching on separate layers.

If you did , then you may just be able to use image size to get to the new dimensions then place the new scan into the image above the background layer, reduce the opacity and use transform to move it into exactly the same place. Then put the opacity back to 100% and you can delete the original background layer. You may need to redo some retouching if the new scan is exposed differently to the old.

If you retouched directly onto the background layer then it is a case of start again.

Dave

[davescm]

One last thing to consider. A larger size does not necessarily require resampling/rescanning to give the same ppi for printing.   Larger images are viewed at a greater distance and so can be printed at reduced ppi.  Have you tried image size , with resample unchecked, and printed to see what it looks like?

Dave

[philips22399292]

This makes sense. Everything was done in separate layers so I will try this. Thanks for this tip!

If that does not work I will try upsampling and do a test.

I will compare upsampled/increased resolution test to a higher quality scan from one image to see how drastic the difference is. 

[davescm]

The best result might be no upsampling. Uncheck resample and just change the image dimensions. There will be less pixels per inch but overall the image will have the same number of pixels as before and at the increased viewing distance used for the larger print will look the same as the smaller print viewed up close.

Dave

[c.pfaffenbichler]

Once again: For »Illustration« have you used Shape Layers and Vector Masks?