Resize -- best practice

[tigh39]

Many years ago, I read the excellent Tom Arah in PC Pro magazine on resizing photos. He recommended resizing in steps, ie 3600px to 3400 to 3200 etc, down to 300px for web images, to maximise quality.

I have been doing this ever since (in Fireworks MX). This is quite laborious!

In Xara Xtreme 5, is this necessary? Should I cut myself free from this habit?

What is your best practice?

[tonylondon]

What is your best practice?

Can't say I've ever done this. Normally I'd keep the original large size photo and reduce it in one go to the desired size or sizes. Then do the final sharpening before saving. It may be I am missing something ...

[instinctive.de]

To anyone with the slightest background in digital signal processing, that approach sounds amazingly wrong and Tom Arah cannot be "excellent" if he truly said that. Every resample (resize) operation reduces the quality of the image as information is lost.

You should only resize once if at all possible.

[Nostaw]

It strongly depends on the downscale algorithm.

The Lanczos algorithms produces good results for downscaling.
http://www.cambridgeincolour.com/tut...ze-for-web.htm

[jclements]

If your are referring to resizing, saving, resizing, .... then image format and whether it is lossy or lossless is important. JPG is lossy and depending on the compression setting, each resizing can cause significant degradation of image quality.

You may want to go to WikiPedia and to get a better understanding.

[gwpriester]

First of all, I would try to work with TIFF no compression images or PNG images. JPEG unless they have 0% compression are lossy and to save space, toss out pixels that you don't see now but may see later.

Then I would do this, reduce one image using the step down and save method and one by just reducing a copy of the image down to size.

View both images at print resolution. If you need the image at 300dpi then change your zoom factor to 288 and see if you can see a difference.

If the image you step and saved is sharper and looks better then you have your answer. But if it is a toss up, then you can probably just do a one or two time resize.