Bitmap images get blurry when you try and make then bigger right?

Question

Bitmap images get blurry when you try and make then bigger right?

Answer 1

That is correct.

Basically, what you're doing is using the same amount of information in a larger area, so "gaps" (holes) appear in the picture.  What you see in the movies when they enlarge a small part of a picture and give all the details, even under a shadow, for instance, is all done in the movies.

Answer 2

All digital picture formats do because they are made of pixels (tiny squares of color).  Really, any media information stored digitally has a level of quality loss.

Answer 3

Well, technically they are more pixellated, not more blurry. There's a difference.  

For the record, blurriness refers to the level of contrast between pixels. You make a picture blurrier by averaging each pixel with it's neighor's colors to reduce the contrast between each pixel and its neighbors.

Pixellation is when each pixel is enlarged to use more than one pixel on the output display.

Despite what you see on all the crime shows, blowing up an image usually doesn't make the image any clearer, and there's no 'magic' program that will enhance an image with any significant reliability. (Google earth looks like you can zoom because they've got multiple resolutions of images already available. It swaps out the image when you zoom in)  

If you've stored an image in a certain number of pixels (screen dots) you can make the image bigger by having each pixel of the photo take up nine pixels of the screen (for example) but this new image has no more information than the last one. You can't create data out of nothing (at least if you want the data to be reliable.)

Making images smaller doesn't generally cause immediate problems in the image quality, but you will lose data, and when you try to re-enlarge that image to the larger size, you will lose clarity.