Image Resizing Question

[Bahamut]

I don't know if there is a program or if Adobe can do this...

For example I have a 70x70 pixel picture, and then try to enlargen it to make it somewhere near tolerable for wallpaper using, it only becomes magnified. The picture becomes ugly and blurred. Is there any way that you can try to clarify those pictures when you resize them twice or thrice their size? Just a question.

[Vaskez]

Hohoho, this question touches on a little thing I like to bitch about
You know in films when they have a digital image of the criminal doing something bad but you can't see their face? Then the hero says "I'll just run it through a filter" and magically the picture becomes clearer. So what, the hero, magically obtained extra image data from the air? The truth is that unless the original image was shown zoomed out and not all the pixels are being displayed, there is absolutely no way that you can enhance the picture because that would mean creating extra image data out of thin air. It always pisses me off when they do that on films as it's a blatant breaking of the laws of physics.

Anyway, the short answer is that there is nothing you can if the image is 70x70 pixels, you can't englarge it and have it look as detailed as before. What you can do is enlarge it a little bit and apply a smoothing filter that spreads the pixel information (such as intensity) around among neighbouring pixels and appears to make the image look better. This works up to a point. So just choose "smooth" from paint shop pro or something.

[Jorath Calar]

no it's very hard.

But if you have Photoshop, resize it in several steps and in each step use gaussian blur... in very small steps.
It's still blurry and ugly but not as much... [img]smile.gif[/img]

[Bahamut]

Yes you got it Vask! I am very frustrated how they do that... well apparently there is indeed a prog but then oh well who knows right? hahaha

Yes I have photoshop, but still, if it's very small, nothing can be done?

[Vaskez]

Hehe, what do you mean apparently there is a prog? I've done a course on image processing so I know how these things are done. As Jorath said, you can apply a Gaussian averaging filter or even a linear one to smooth it some and that will work up to a point.

They can also interpolate between pixels, so e.g. if you have a greyscale 8bit image and you have a pixel of intensity 20 and another next to it with 40 then you can create a new pixel of intensity 30 between then for example. This way you can create new information but whether the result will look realistic or not depends on the subject of the picture. I haven't tried it, but I doubt it'd work for faces. Might work for wallpaper but I don't know which program has such a feature.

Again, in short, yes there are lots of image processing techniques that can help you seemingly enlarge a picture and create extra pixel information to fill in the gaps that appear when you enlarge, but what you seek (perfect enlargement) is physically impossible so don't expect to see it in the near future

You can even do a little test to see why. I've done it. I wrote some C code for enlarging images. When you magnify, gaps appear between the original pixels which move further apart. The reason gaps don't appear when you enlarge an image in professional image editing packages is I think because they just copy or average the neighbouring pixels of a gap to fill in the gap. That's why it looks ugly.

[ 07-11-2004, 07:23 AM: Message edited by: Vaskez ]

[Bahamut]

Ahh... thanks Vask.

Even if I did interpolate on those pixels, I don't think I would be satisfied with the result. Tsktsk.

[Lauren]

Originally posted by Jorath Calar: no it's very hard. But if you have Photoshop, resize it in several steps and in each step use gaussian blur... in very small steps. It's still blurry and ugly but not as much... [img]smile.gif[/img]

There are some programs similar to photoshop that you sometimes get when you buy a scanner.
In them they have different art changing buttons, you can blur the picture, make it clearer, make it bigger, make it darker, make it lighter, ect ect.
Unfortunately I do not know the name of the program at the moment, but I will find out for you as soon as I can find it.