How to turn picture into large printable poster?

Is there any possible way you can turn a 445x446 picture into a 800x630 poster?

• without the poster looking like crap?

• Answer:

  When you increase the size of an image you can not add more detail you can only add more pixels which contain the same amount of information as the smaller image. So, no you can't really increase the size of an image without loosing resolution. But there is a way around it, but your image will not have quite the same quality as an image that was originaly that larger size. Your best bet is to start out with a hard copy of the image and scan it at the resolution you need. If you only have the digital version of the image, bring it in to Photoshop. Increase the image size to the desired size. You will notice when viewing it at 100% the loss of quality. Go to Window, Channels and work each channel individualy. I like to apply a combination of Dust and Scratches and Blur filters to each channel. The reason for working with each channel by itself is to avoid blurring the image too much- for instance you might find that the image looks better with more blur on the blue channel than the rest. Also, some printers will print lo-rez files better than others. So, the printer can make a difference too.