The Best Image Resizing Software: Topaz Gigapixel AI vs ON1 Resize AI

by Jul 15, 2022Photography Blog

Robin Whalley Landscape Photographer

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The Best Image Resizing Software: Topaz Gigapixel AI vs ON1 Resize AI

In recent years we’ve seen an explosion of photo editing software using AI or artificial intelligence. One popular application of this technology is in image resizing. Many of the packages claim a breakthrough in quality and that they are the best image resizing software. In this article, I’ll be putting two popular AI image resizing packages to the test to decide which is best.

Of the two, Topaz Gigapixel AI (affiliate link) was the first to launch and is now at version 6. In contrast, ON1 Resize AI (affiliate link) only launched recently and is still at version 1. I have tried both, and both appear to produce good results when enlarging images in isolation. It will be interesting to compare the results and see how they perform head-to-head.

The Best Image Resizing Software title image

Judging the Enlargement Tests

To identify the best resizing software between the two packages, we are only considering one aspect, which is image quality. The software that produces the best quality image enlargement when viewed at 100% magnification wins.

This means that won’t be looking at any of the additional features both packages offer. In fact, to make the comparison fair we will only use the default settings where possible. This probably means these won’t be the best quality enlargements possible. If you want to repeat the exercise using the trial software and spend time optimising the settings, you should be able to achieve better results.

The Test Images to Resize

We will be performing three enlargement tests, each using a separate image. Two images are landscapes and the third is a portrait which I downloaded as a JPEG from a Stock Library. You can see the images below.

Test resizing image 1

This first image was captured using a Fuji XT3 with Fuji 10-24 lens. It was captured as a RAW file and converted to a 16bit TIFF image using DxO PhotoLab 5 Elite. The RAW processing applied DxO DeepPRIME noise reduction and lens correction modules. At a 300dpi resolution the image would produce a 21 x 14-inch print.

Test resizing image 2

This second image was downloaded from a Stock Library in the JPEG format. I don’t know what camera and lens were used. Reading the metadata in the image, it appears to have been processed with Photoshop.

Test resizing image 3

The third image was captured as a RAW file using a Panasonic G9 with Leica 12-60 lens. It was processed to a TIFF image also using DxO PhotoLab with similar settings to the first image. At a 300dpi resolution this image would produce a print of approximately 17 x 13 inches.

Producing the Test Enlargements

For the testing, all three images were enlarged to produce images which measure 60 inches on the longest edge at a resolution of 300dpi. That’s and enlargement of approximately 280% to 350% depending on the image.

You can watch the testing and see an assessment of the results in the following video. Then below the video you will find some of the samples used in the video so you can see the results for yourself.

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Enlargements Compared

Due to the size of the images produced, sharing all the results in this article isn’t possible. If you would like to download all the comparisons to check on your own computer, you will find them on the Lenscraft YouTube Images page.

Here is the first sample from the first test image.

resized image sample 1

Please click the image to enlarge as the down-sampling of the web display makes the Topaz Gigapixel enlargement on the right appear sharper. When viewed at the correct resolution, the ON1 Resize AI sample on the left appears sharper. This makes me suspect the Topaz Gigapixel enlargement would produce the better print of the two.

One problem I did notice when comparing the two is that the ON1 Resize enlargement looks a little false, as if the detail has been over enhanced.

Here is the sample from the second image of the portrait.

resized image sample 2

As with the first image, please click to enlarge the sample.

Here the ON1 Resize enlargement on the left appears softer than the Topaz Gigapixel enlargement on the right. In the Gigapixel enlargement the detail in the skin, and especial the hair, appears overly sharp and detailed. The ON1 Resize enlargement is softer and is much more natural.

Here is the sample from the final image.

resized image sample 3

As with the other two images, please click to view the sample at the correct resolution.

In this comparison, the ON1 Resize enlargement on the left again appears too sharp and detailed. The Topaz Gigapixel enlargement on the right is softer (but still sharp) and appears more natural.

Enlargement Problem

If you watched the video, you know that I mention a problem. I noticed with some ON1 Resize enlargements there was a pattern that wasn’t present in the Gigapixel enlargement. Here’s a comparison to show the issue. Please click the image to view at the correct size.

problem resized image example

In this comparison the ON1 Resize enlargement on the left appears to have more fine detail at first glance. But something also looks a little strange about the detail, as if it’s a repeating pattern.

When you compare the detail in the rocks and grass carefully, the ON1 enlargement appears to have a mesh like pattern overlaid on it. This wasn’t present in the portrait image, but I did find traces in some areas of the first landscape.

Following further testing, my Panasonic G9 images appear more prone to this effect, although we should keep in mind that they were enlarged the most. With smaller scale enlargements I didn’t notice the effect the same. I’m not sure what has caused the “mesh pattern” but I have seen something similar in the past with other software. I even published an article reporting a possible AI problem.

And the Best Image Resizing Software Is…

Both Topaz Gigapixel AI and ON1 Resize AI produced good enlargements in this testing, and I would be happy to use both. The ON1 Resize enlargement of the portrait was particularly good although it is possible to improve the Gigapixel enlargement using the facial recognition feature.

Taking everything into account, the winner of this comparison is Topaz Gigapixel. It was very close between the two packages but as I’m a landscape photographer, I can’t ignore the better landscape enlargements from Gigapixel.

I will also add that when performing these enlargement tests, I noticed variations in the results. These appear to be due to different cameras and RAW processing. I therefore recommend conducting your own tests on both packages before making a purchase decision. My results may not reflect the results you will see from your own camera and software.

You can download a trial version of Gigapixel (affiliate link) from the Topaz website. For a trial version of ON1 Resize AI (affiliate link) visit the ON1 website. ON1 Resize AI has also been integrated into ON1 Photo RAW since version 22.5 so owners don’t need to purchase the separate package.

If you decide to purchase an ON1 product, please apply the code LENSCRAFT20 at the checkout for a 20% discount. [ON1 may choose to vary or discontinue the discount program in the future but at the time of publishing the code is valid]

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