How to significantly enlarge digital images

[wizpeep]

I would like to significantly enlarge some digital images 2800X2100
to print out at A1 or A0. Has any body any suggestions or experience of doing this. I can think of 2 possible solutions
1. Vectorising the images
2. using some software genuine fractals or Photo Zoom

Has any one experience of doing this and how effective were the results.

 

[Welles]

Are the digital images photographs? If you are talking about graphics and can possibly go vector that would be the strategy of choice. If I understand properly, you are starting with 2800 x 2100 px and are going to uprez to 7023 x 9933 or 9933 x 14046 (presuming you are saving at 300dpi) I think you have enough pixel data to get an adequate result at the A1 size but it will be a bit questionable at the A0 size

No matter what you do, there will be significant degradation of the image but then you won't be looking at it close up either. I've often uprezed images from 2250 x 3000 to 4500 x 6000 (USC) and was perfectly happy with the results. You can get a good idea of the quality of the final print by viewing your enlarged file at 25%. That will be a bit smaller than final print size but will give you a good idea of what you will see printed and Photoshop renders 50, 25, 12.5 and 6.25% screen reductions without anti-aliasing display issues. Now imagine moving back from the image until the whole thing would be in your field of view.

I've used Genuine Fractals in the past and used to swear by it. I've also tried the 'stair step' technique of uprezzing but now feel that the new PS algorithms of Bicubic Sharper and Bicubic Smoother are as good as anything available and I uprez in one action rather than the multiple steps which many seem to tout. I have not tried Photo Zoom.

 

[theKeeper]

I concure with Welles on this. :B