Speed comparison of 10 batch image resizers

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Speed comparison of 10 batch image resizers

Published by on July 6th 2008.

After adding multi-core and multi-processor optimizations to Picture Resizer a few months ago, I was wondering how it compares to other tools for image resizing in terms of speed and image quality. Finally, I have found a bit of time to pick 10 applications and put them through a simple test.

How I tested

Test system:

  • Intel Core 2 6600 (2.4 GHz, two cores)
  • 2 GB of memory
  • Windows Vista

Test data:

  • 102MB in 98 .jpg pictures
  • various sizes, mostly in range from 2 to 6 megapixels


  • 90% output .jpg compression quality (if supported)
  • resizing to 800 pixels longest side (if supported)
  • coverage-based resampling method (if supported)


ApplicationTime (lower=better)Note
VSO Image Resizer
Picasa 216sfailed to process large image *)
Picture Resizer 3.017s
Irfanview 4.119s
JKLNSoft Batch Image Resizer 2.8820s
Microsoft Image Resizer PowerToy22srun on XP, lower quality output (cannot set compression quality)
XNView 1.93.627s
ACDSee Photo Manager 1027s
RealWorld Photos 2007.1 beta45s
Adobe Photoshop CS3110sfailed to process large image *)

*) Picasa and Photoshop refused to resize one of the test images, 40784×100 pixels stripe of a gigapixel image (http://www.tawbaware.com/maxlyons/gigapixel.htm)

Resized pictures per second.

A word about image quality

Quality of the resized pictures was satisfactory and there were only minimal differences among the tools. With one exception:

Images produced by Microsoft Image Resizer PowerToy suffered from a strange artifact. There was a white line by the right and by the bottom sides of the resized pictures. This tools seems to have problems with the boundary conditions of its resampling algorithm.

Strangely enough, Picture Resizer 3.0 was the only tool aware of gamma correction. Every other tool totally ignored the fact that 99.9% of .jpg pictures do not have a color profile and made the resampled pictures darker in regions with large differences between neighbor pixels in the original image (this usually affects edges). RealWorld Photos and Adobe Photoshop are of course able to handle gamma correction, but this must be specified manually and how many users are going to bother themselves with that? Probably none.

Gamma correction brightness difference.
Ignoring gamma correction makes resampled images darker.

About individual tools

VSO Image Resizer


This tool was the fastest of the tested ones. While the difference is not big, it is still a victory. The user interface of the tool is nice and it is free for personal usage, although it pops a dialog each time the tool is run.

Google Picasa


Picasa is a photo organizer, but has a very fast image resizing function. On the other side, the resizing is a bit clumsy, because pictures need to be added to the library first and only then it is possible to resize them. Picasa was also unable to load the extra-large image.

Picture Resizer


3rd place is not bad, but I should do some more performance tuning in the next release. Picture Resizer is a very simple-to-use tool and users can resize pictures by dragging and dropping them on the application icon or by running commands from context menu. It is the only tool, which is by default gamma-aware and it is the only one that does not need installation and hence it is 100% portable.



An old and popular freeware image viewer (and more). Nice 4th place ;-). No significant pros or cons. Made registry entries without asking, but deleted them on uninstall.

JKLNSoft Batch Picture Resizer


A tool specialized on batch resizing, a bit slower than the other ones, but not significantly. The user interface could not cope with my desktop running in 120DPI and looked a bit garbled. Considering this is a commercial tool, while all of the previous ones were (at least for personal usage) free, one would expect better result.

Microsoft Image Resizer PowerToy


It does its job, with the artifacts mentioned above. There is no way to set compression quality. If this tool were not distributed by Microsoft, I doubt that anyone would use it or even know about it.



Nice free (for non-commercial use) image viewer. Acceptable resizing speed.

ACDSee Photo Manager


A commercial image viewer and organizer. Acceptable resizing speed. Annoying multiple popup message boxes and issues with uninstalling. It made registry entries without asking and did NOT delete them on uninstall :-(.

RealWorld Photos


RealWorld Photos (still in development) will be a general purpose batch image processor and photo editor, focused on more complex operations than just resizing. It is understandable that a more generic tool is slower than a specialized one.

Adobe Photoshop

Adobe’s all-in-one solution for image editing and batch processing. Again, it is understandable that a generic application is slower than the specialized one. Setting up the custom action was not exactly easy.

It was quite a surprise that Photoshop was unable to open the extra large .jpg image while many others had no problems with it. One would expect better from an application like this.


The numbers speak for themselves. It should be clear that resizing with Photoshop is not the best idea when speed is a concern. The quality of the resized pictures was almost identical (save for the gamma-correction issue). The speed differences of the first 5 tools is not big and you should take other aspects into account (like ease of use) when choosing your favorite image resizer.

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