All forums => ThumbsPlus Suggestions => Topic started by: mjgraves on 2016-01-29 13:52:26

Title: resize quality
Post by: mjgraves on 2016-01-29 13:52:26

Firstly, I've been a TP using since v4. Love the product, have recommended it countless times.

The single most common thing that I need to do is resize images for use online. I've never been able to use the resize function in TP to accomplish this. It simply doesn't produce acceptable results.

Consider the following example. It's a [link=]product photo[/link] that originates as a 1500 pixel wide JPEG. I need it scaled to 300 pixels wide.

I did this in TP10 and Photoshop CS4, putting the results side by side for comparison. It's been scaled to 200% for display purposes.


It's not clear to me why TP10 doesn't do a good job. If it were able to perform clean scaling it would save me hours of going between TP and PS.

Is there anything that can be done to improve this function?

Many thanks,

Michael Graves
Title: resize quality
Post by: Daan van Rooijen on 2016-01-29 16:04:42
When you use the regular Downsample algorithm, you'll get a result very similar to the Photoshopped image. Add a bit of Unsharp Mask (strength 2) to enhance detail and TP's result will look like this:


Edited to add:

Perhaps interestingly, I find that I get a very subtly better result when I first increase the bitdepth to 48 bits (Image | Mode | 48b RGB). It maintains detail a bit better and jaggies seem less pronounced:

Title: resize quality
Post by: mschnell on 2016-01-30 17:17:36
Anyway, it would be nice to have the option to select Lanczos (as available in the free IrfanView software) which does a rather good job avoiding alializing  s well with up as with downsampling.

Title: resize quality
Post by: Daan van Rooijen on 2016-01-30 17:24:34
Fully agreed! :-)
Title: resize quality
Post by: mjgraves on 2016-01-31 14:50:21
That may be so, but it merely underscores the fact that this aspect of the software under-performs. It's unchanged in many, many years. It ought to work better at default settings, without resorting to multiple steps