I use the previously described Perfect Resize but an excellent free program for changing image resolution is FastStone Rhoto Resizer. I would recommend the Lanczos 3 algorithm for enlarging. Stepwise enlarging as others have described will probably get the best results
As the person above explained quite well the only way to have a decent result in increasing size is too do it by increment ( you can use a photoshop action that increases ten times 110% back to back or use specialty plugins like mentioned from On one ... Vertus also has a good one and alien slin too. I understand that you just wanted a couple bigger and that you have picasa but do you know like from what starting size to what desired size you need? If it's only a couple and they are easily accessible I am willing to help you out if you dont feel like getting proper software good luck
Sure you can. That's what enlargers exist for. Mine's a Beseler. You should rephrase that and say that you can't make something bigger and maintain or improve the quality. Even then it isn't quite true, but it would take an unbelievable amount of work, editing the whole photo one pixel at a time, and it would absolutely not be worth it. You'd be sick to death of that photo, and might die of old age, before it was done.
Depends on your skill level. I know a guy who restores old damaged photos. I'm pretty good at things like spot toning and blemish removal, I don't need a computer to do it, and you can't find what I did even if you look for it with a loupe. I'm pretty good at editing with a computer too, and I don't need much of an editing program to do it, but he can do stuff that is unbelievable. He could probably do it.
You’re damn right about that. I once had to take a bad scan of an offset printed image of a CEO that was about half an inch square and blow it up to lifesize. Took me three days. I didn’t try to go for photo-realism, but made it look more like an oil painting. The eye details were the worst. Made quite a bit of money, though.
Worst one I ever had to do took me a little over a month. That was just getting rid of artifacts from a bad scan. Unfortunately, I was going for realism. I didn't have a serious image editing program at the time and had to do it in paint.
This was before I had real clients. I was doing it for a magazine cover that I hoped to sell on spec. To get an idea of how long ago this was, I had my first brand new computer at the time and it had Windows 3.1 with a 2400 bps modem. It was a selling point, because most of the other computers in the store had 1200 bps modems. Downloading one decent quality 8x10 photo could take half an hour or more. Digital cameras existed at the time, but you usually couldn't tell what the subject in the photo was supposed to be, probably because there were only a few people who had learned what a megabyte was and only a handful dreamed of one day having more than one. We were still 3-4 years away from Sony's camera commercial wherein they talked about magabytes in the plural. Pretty much everyone was using film back then.
That’s tricky, and while it’s possible to get a moderately decent result, it’ll never look as good as an image that was shot with a higher-resolution sensor to begin with. Since you’re using Picasa, I can’t tell you the specific commands (never used it myself), but this technique has been known to work fairly well in Photoshop and it might produce similar results, assuming Picasa is using similar interpolation algorithms.
The trick is to increase your image in small increments. Try enlarging it to 110% of its original size, then do it again, and again, until you’ve got it to about 200% or so (twice the original size). Your image will suffer a bit of softness (since, as ~photomark mentioned, you can’t really get something for nothing), but you can run a sharpening filter on it at a low to moderate setting to make it appear sharper – just don’t overdo it or you’ll end up with odd haloes around edges, especially where there are light/dark divisions. In the end, you won’t see any more detail, but your image will be larger. Note that I wouldn’t recommend trying to scale up any image to more than 200% its original size.
Note also that this technique works best with photos that are generally soft and/or diffuse to begin with. Something shot completely out of focus can be scaled up almost infinitely, because there’s no real detail to begin with. On the other hand, shots with lots of sharp details, angular lines and a large depth of field will not fare as well.
As an alternative, there are programs available (onOne software makes one called Perfect Resize) that can do a remarkably good job of scaling up images as much as 1000%. Again, still not the same as taking the photo with a higher-resolution camera to begin with, but it makes for a good compromise in a pinch.