Downscaling image without quality loss

[Ashley0432]

I'm designing business cards so the canvas is quite small (85mmx55mm) roughly

I have a high res RAW image and when I reduce the size of the image to match the canvas, there is a significant loss of quality. I have tried converting to smart object and using the 'bicubic sharpner' but this doesn't seem to have any effect.

Is there any way of preserving quality when doing this?

[c.pfaffenbichler]

Could you please post a screenshots taken at View > 100% of both states and with the pertinent Panels (Layers, Channels, Options Bar, …) visible?

https://forums.adobe.com/thread/963429

[Ashley0432]

Its hard to tell quality loss at 100% but there is quite a lot when zoomed in.

[c.pfaffenbichler]

Its hard to tell quality loss at 100% but there is quite a lot when zoomed in.

And it’s irrelevant, provided you actually scaled down to the intended/necessary pixel dimensions.

Why CMYK by the way?

[Ashley0432]

The print company asked it in CMYK format.

[JohanElzenga]

Quality loss is inevitable when you downscale. When you have fewer pixels to make up the fine detail in the image or the gradient in the sky, then you will get a lower quality as result.

[c.pfaffenbichler]

Did they tell you which exact CMYK Space they utilize?

And are you sure the image has exactly the right dimensions and resolution now?

You can still sharpen the Smart Object (for example with Unsharp Mask).

[Ashley0432]

They didn't say, just that it needs to be CMYK.

[c.pfaffenbichler]

»CMYK« is pretty much a nonsensical requirement as there are numerous CMYK Spaces with hugely different properties.

Are you sure you understood them correctly?

Or might they be a printshop that does not care about quality?

[Terri_Stevens]

When you reduce the size of your image to match the canvas, are you also attempting to reduce the file size by 'downsampling' or is the objective to just resize the original image? If you are just altering the dimensions of the raw image it should not decrease in quality. As you are using 'Bicubic Sharpen' , I would assume you are actually 'downsampling' ie throwing away pixels. If you uncheck the 'Resample' box you can alter dimensions but not decrease the pixel count and not lose quality.

[JohanElzenga]

https://forums.adobe.com/people/Terri+Stevens  wrote

When you reduce the size of your image to match the canvas, are you also attempting to reduce the file size by 'downsampling' or is the objective to just resize the original image? If you are just altering the dimensions of the raw image it should not decrease in quality. As you are using 'Bicubic Sharpen' , I would assume you are actually 'downsampling' ie throwing away pixels. If you uncheck the 'Resample' box you can alter dimensions but not decrease the pixel count and not lose quality.

Don't fool yourself. If you change the dimensions without downsampling, you'll increase the resolution. As the printer will normally not be able to also print at this higher resolution, you'll just transfer the problem to the printer. Now the printer will have to do the downsampling (and might do a worse job)...