Is Windows Picture and Fax Viewer doing some image processing?

[whitestone]

1) If I take a jpg image (made with a high end dslr at high

resolution) and open it with Adobe Elements 3 and zoom way in (1200%)

I can see the pixelated nature of the image. However, it I open the

same jpg file in Windows Picture and Fax Viewer and zoom in the same

amount, the pixels are much less distinct -- it looks almost creamy

smooth. What kind of processing is going on in Windows Picture and

Fax Viewer, and can it be duplicated in Elements? Even zoomed back

out to about 100%, I can see a difference between the two programs:

for example (for this same image and magnification) catch lights in

the eyes have a pleasant softness in Windows Picture and Fax Viewer,

while they look a bit blocky in Elements.

 

2) If I open the same jpg image in Elements and zoom way out so that

the entire image is about 4 by 6 inches on my screen, then I can see

that a sharp edge (say, for a light to dark transition) is pixelated,

due to (I would think) the limited amount of monitor pixels. However,

for the same image at the same magnification, Windows Picture and Fax

Viewer shows the same edge without the 'jaggies'. Why is there a

difference?

 

Thanks!

[steve_dunn2]

<p>I don't know what Windows picture and fax viewer does when you ask it to scale a photo up or down for display. I know there are some other viewers which allow you to determine what algorithm they use to do this; Irfanview is an example. The simplest way is to drop or duplicate pixels; this is very fast but tends to produce effects like you're seeing in Elements (jaggies when reducing the picture, blockiness when enlarging the picture). Other resampling algorithms can produce better results, but at the cost of taking more time (substantially more in the case of larger pictures and/or slower CPUs).</p>

 

<p>There's a good reason why an image editor like Photoshop Elements does what it does, at least when displaying the image at >100%. If you're trying to edit it, you want to see the actual pixels. For instance, if you're doing something to the edge between a light area and a dark area, you want to see the pixels which make up the edge, not some artificially blended/smoothed gradient.</p>

[Stock-Photos]

The smoothing your speak of is interesting indeed. I tried it and saw the same lack of pixel magnifying.

 

This could explain why that application is so slow between zoom steps.

 

On a different but somewhat related note, I have the Windows Media Center version of XP. When I do a slide show with Media Center, there is a drastic loss of sharpness in the displayed files. This reduction in sharpness would be less noticable viewing further away from the screen, as one might be, viewing HDTV.

[JeffOwen]

Interested by this thread I did some screen copies of the same image using Picture & Fax viewer, ACDSee and Photoshop at about 700% mag.

You are quite right the Picture & Fax viewer seemed to be able to smooth out the pixelation on the screen. I don't know how it is done but I guess it could be achieved in PS by increasing the pixel count.<div></div>

[JeffOwen]

Looking at the 3 images I have just posted doesn't quite show the full effect.