Increasing the physical size of an image

[Happy_coder]

Hello all

I have a problem, which I guess is a common one but I can't find an answer to the problem on the net which makes sense to me (being new to Photoshop).

I have been given an image which I need to increase in size so it can be printed on a  board 1m (w) x 2m (h).

The dimensions of the image I have been handed is 90mm(w) x 134mm(h) and a resolution of 72dpi.

Now the client and myself nows the printed image will not be great quality. It's a photograph taking a long time ago and this is the best quality image to work with.

As a novice I would simply increase the size of the image to 200% and select the resample 'Bicubic Smoother (enlargement)' option.

I would then save the layer as a smart object and use the Smart Sharpen filter to try and make the image sharper.

I know there are advanced techniques to further improve the final print quality, but are my steps above okay for my needs??

Or can you suggest another workflow??

Thanks for your time.

[Derek Cross]

You have an original image that's around 250 x 370 px that needs enlarging to something like 16000 x 8000px for printing at say 200PPI.

I should hand the image back, it can't be enlarged to that size effectively.

[gener7]

I would see what "Preserve Details 2" in CC 2018 will do for you. Since large sizes are not meant to be looked at close up, you might try a sample print and see how it goes.

[D Fosse]

250 x 370 pixels isn't an image, that's a thumbnail. Even if it's an old photo, there must be a higher resolution version somewhere. Nobody would ever scan a photo to 250 x 370 pixels, even at the very beginning of digital image processing.

Blowing this up to a 1 meter print is...completely unrealistic, to put it politely. Whatever the method.

[barbara_a]

The best solution would be to somehow get the original image and re-scan at a more realistic size and resolution.

Baring that, you might try applying some filters to make the image appear stylized so that it will look like you meant it to be more design-like, not realistic.

[Happy_coder]

Sorry, I'm an idiot. I did warn you....;)

The dimensions of the image is 900mm(w) x 1134mm(h) with a resolution of 72dpi.

We are aware the print quality will still be poor. It won't be viewed close up and as it's a historical image from way back, the poor print quality actually adds to the effect. I just want to get the quality as good as possible.

Thanks for all your replies. It's much appreciated.

[davescm]

Hi

There are two ways of doing this and each is a trade off.

Before we start - you will need to crop your image to fit the aspect ratio of 1 :2

Method 1 - Use bigger pixels

In image size,  uncheck resample and change the resolution from 72 ppi to 40ppi. This will make the pixels bigger but that might be acceptable depending on the intended viewing distance

Method 2 Resample
In image size - check resample and enter your new dimensions and use Preserve Details 2.0 as the algorithm (that is the latest algorithm from Adobe)

Which is best - it depends on your image and the viewing distance . Using the first method the increased pixel size will be visible, using the second the pixels may not be visible but there will be some softening.  Take a small section of the image and print it at say A4 using each method. View it at the intended viewing distance for the large print and let your eyes decide.

Dave

[barbara_a]

Giving the image a sepia tone might add a better look to the image.

If you show the image you might get more specific suggestion.

[D Fosse]

sh6ixs  wrote

The dimensions of the image is 900mm(w) x 1134mm(h) with a resolution of 72dpi.

OK, now that's something else entirely.

Generally, the fear of visible pixels is often overrated. Mark an inch on the wall, then divide it up into 40, and step back...that's pretty hard to make out.

IME resampling always introduces very unattractive artifacts. Worst case, if the original is a jpeg, you get an image covered in a "worm-like" structure, which is how the jpeg compression blocks enlarge. Leaving the native pixels clean always looks better.