enlarging low-resolution pictures...

[VJ]

A friend of mine would like to have some holiday pictures enlarged. However, they are only 640x480 (her camera was set to low resolution), so I don't see this happening in proper quality.

Still, are there ways to enlarge a picture (I assume in combination with smoothing it) to have better quality than just a normal enlargement ? (as to make the bad quality less visible )


Jörg

[GNEP]

Just print them out as they are but stetched out on really big paper, and then wear someone else's spectacles when looking at them

[GuchiGuh]

print them out on highest quality paper and on highest print settings in orignal size. Scan them on highest resolution possible.

[VJ]

GNEP: hehe...

GuchiGuh: hmm, do you think this will work ? I could try scanning a 310 dpi 4"x6" print and see how the image looks... It could be that the print caused some smoothing, but wouldn't this be possible in some photo-editing software ?

Jörg

[az]

Maggi has some good enlargement software on his hands, I believe, but I doubt that it can do wonders.

A trick is to ADD some noise - the brain then interpolates, which it does better than any software could.

And she should learn from her mistake to never skimp on image quality and size again and rather buy a new memory card.

AZ

[chaoliang]

There was one software which was said to be capable of enlarging pitures losslessly. I'm sorry for forgeting its name. It was bundled with the North American versions of Nikon Coolscan film scanners. In Europe the SilverFast was the case.

I'll make the same suggestion as GuchiGuh.

[Paddy]

I'd say GuchiGuh is mistaken.
The quality will only be as good as the source.

[GuchiGuh]

hmm....i once scanned a book cover for an assigment back in 1997. I used max resolution (i was computer newbie then) so the image took about 3 hours to get onto my computer.. when i then openened the image (which took another 30 minutes) it was damn high resolution and very good quality. and of course absolutly massive in size! (both pixel x pixel size and MB size...)

[az]

So?

AZ

[chaoliang]

The trick is to scan in high resolution and resample it down.

[Duty]

Originally posted by chaoliang
The trick is to scan in high resolution and resample it down.

That would be my first choise as well, or for an image of that size press to a 4x5 negitive and re-scan.

It will never be the best quality but the process does work to some degree.

This is one way to create poster size images from media normally to small. The draw back is that it will end up grainy, at least more so then normal. But with some work (time consuming) it can look good.

Good luck,

Jeff

[Indiana]

Originally posted by Paddy
I'd say GuchiGuh is mistaken.
The quality will only be as good as the source.

Guchis suggestion can in fact work, IF you have a very HQ printer. Then scan the thing at 600dpi and scale it down again afterwards to a more convenient resolution (e.g. 2272x1704 as is delivered by 4MP digicams).

But I believe that only works similar to the way az suggested (adding some random noise, thus making the scaling and the low res of the original less visible to the human eye)

[GuchiGuh]

Originally posted by az
So?

AZ

i forgot to add the point oops sorry.
Hmmm the point is that a small image was turned into a REALLY HUGE ARSE HIGH RESOLUTION picture.

[Nowhere]

But you didn't add any details in the process - the same (or ~) can be done digitally.


zima

[Belwarrior]

GuchiGuh's method doesnt always work well in all situations but it is worth the shot.. To get a good enuff pic i scanned it in at 1200 dpi (or next highest) then i was using staroffice 5.x to remove noise, smooth it (and optionally sharpen it just a little bit to see if it looks better - sharpening could make the picture look worse) and reduce the image to about 1600x1200 resolution. For printing, I find the quality loss is not too bad if the pic is larger than the media and the picture is resized to fit the media.