Upresing Image

[SRPcashie]

Hi All,

I have an image that is several years old and much lower res than I am used to these days.  I need to get it ready for a large printing on metal for a public art project I was just awarded.  I'm not used to printing or upresing so I'm looking for detailed instructions on how to go about it for best results.

The image as it is as a 8 bit tif is 62.9mb's and says it's 19x12 inches at 300dpi.  I need to print it at 60 inches wide as a b/w image.  

Any thoughts?

Many thanks,

Silvia 

OS Catalina 10.15.6

PS 21.2.1

[Ussnorway]

can you share this image?

[Nancy OShea]

As a rule, up-sizing images is a very bad idea.  Adding pixels where none exist introduces unwanted artifacts and pixelation.  That said, I would discuss this with the print professional.  They will know what the best approach is for the paper, size, ink and process they are using. But don't expect miracles.  60 inches is a far cry from the original.

[SRPcashie]

Thanks Nancy.  I completely agree, but in this case, it cannot be helped.  It happens.

[Conrad_C]

The best place to start is using Image Size with Preserve Details 2.0 selected as the Resample method. It should preserve details much better for enlargement than any other choice in the Resample menu.

But the higher the percentage of enlargement, the less the details might hold together. If the resulting file doesn’t meet your standards, you may need to use specialized upsampling software such as Topaz Gigapixel AI, which is well-regarded for this kind of thing, but requires a powerful GPU and is another $100.

Also, ask the metal printing service what ppi resolution they recommend for a work of that size. 300 ppi is probably not recommended because it would create a very large file size at 60 inches, and if the work is designed to be viewed at a distance, a lower ppi resolution will be perfectly adequate. I just don’t know what the guidelines are for ppi on metal at specific art sizes and viewing distances.

[Nancy OShea]

Yes, I agree the viewing distance and PPI will be big factor.  That's why I said talk to the print professional.

[SRPcashie]

Is it still important to upload a small percent at a time?  I remember that being a thing, like 120% at a time. This is going into a public art collection so it's possible it will be seen from not so far away.

[Conrad_C]

The advice to scale up in small steps is, as far as I know, not necessary or no longer better, ever since Adobe added improved upscaling methods. Now you can simply use one of the improved methods in just one step.

[SRPcashie]

So you should use Preserve Details 2.0 rather than Preserve Details enlargement?

[Conrad_C]

Short answer:

Yes, Preserve Details 2.0 is the newest one. It’s supposed to be noticeably better than Preserve Details.

Long answer:

The more important the project, the more important it is for you to test how good your specific artwork looks when upscaled with different options. You get a lot of choices because the best resampling method can sometimes depend on what’s in the image content (edges, color transitions…). You don’t have to test them all because not all of them are relevant to upscaling photo content; for example, some are better for screen shots or web graphics.

For fine art photo enlargement, consider running tests that compare:

Preserve Details 2.0 

Preserve Details 

Bicubic Smoother 

Bicubic Sharper 

Bicubic 

If you don’t want to try them all, concentrate on the first three. And if you want the tests to run faster with smaller files, make a copy of your photo for testing, crop it down to an important area (without resampling of course), and run the upscaling tests on that. Keep an eye on edge quality, pixelation, smooth transitions vs banding, etc.

[D Fosse]

"in this case, it cannot be helped"

Why, exactly, can it not be helped?

19 x 12 inches at 300ppi is 5700 x 3600 pixels. That's not a particularly small image! In fact, it's big enough to work as-is for almost any practical purpose, if the image is otherwise of good photographic quality (in focus, no camera shake etc).

I'm with Nancy on this. Upsampling is almost always a bad idea, no matter what fancy algorithm you use. There is absolutely nothing to be gained, but a whole lot to lose in terms of artifacts which you always get with upsampling.

The only justification for upsampling, ever, is if you can actually see individual pixels. 60 inches wide just means you'll be seeing it from a greater distance, so the effective optical resolution stays the same. You'll want to step back. The eye demands it, so that you can take in the whole. Standing up close is physically uncomfortable.

You will always get the cleanest result by leaving the file as it is. Instead, spend your energy on optimal sharpening.

[mglush]

Hi Sylvia,

I also have had to upscale images because of not having an original to go back to--I agree sometimes it can't be helped. I have had really good results through the years at uprezing at 150% until I get to the size I want and have had some very good results.

Let us know how it turns out!

Michelle

[D Fosse]

I think we need to get this out of the way: you do not need 300 ppi for large format prints. That's a very common misunderstanding. As size goes up, ppi requirement goes down, because it will be seen from a greater distance. Large wall-sized banners can be as low as 15 ppi and still look razor sharp.

A good quality image will work at any size, whether magazine spread or roadside billboard.

Even so, 300 is not a magical number. 300 ppi is for book and magazine print to be seen from less than arm's length. This is usually printed with a line screen frequency of 150 lines per inch. With an original image at 300 ppi, that means individual pixels can not possibly be distinguished in the final print.

In other words, 300 ppi is a theoretical upper limit, beyond which no improvement is possible. 300 and 400 is all the same, you can't see any difference. But you can go quite a bit lower before you see any noticeable drop in sharpness.