| Image Dimension, Size, and Resolution | |
|---|---|
| Computers understand images through a pixel-based data-structure, which may be understood simply as a 2d grid of squares. As a result, when discussing size and scale of images we must take account of two basic properties: Image dimension, which describes how many squares there are, and image size, which describes the 'physical' size of the overall grid. The relationship between these two is called 'resolution'. | |
| Part of | Photoshop CS5 |
| Part Type | Entity |
| Screenshot |
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Computers understand images through a pixel-based data-structure , which may be understood simply as a 2d grid of squares. As a result, when discussing size and scale of images we must take account of two basic properties: image dimension , which describes how many squares there are, and image size , which describes the 'physical' size of the overall grid.
These two properties are only indirectly related: Until you specify how large each pixel is (a relationship referred to as image resolution ) an image has no specific size. But resolution and size aren't innate to a digital image; they're fungible qualities. That is, the same 100-by-100 pixel image can be made as small as a postage stamp or as large as a billboard.
Description below borrowed from How Color Works in Photoshop by Fraser and Blatner.
Image Dimension
Image Size
Image Resolution
{{todo|discuss image resolution, discuss how to change it
72dpi
is what most computer screens use, while
150dpi
is the minimum resolution that you should use if you want to print an image.
If the paper size in which you will print a raster file is similar to the size of the document, the resolution can even be 100dpi. If you will probably need to print it at a larger size, you can go up to 300dpi. Remeber that the higher the resolution, the bigger the file, so the more memory you nweeed in your computer to handle it.
A rendering's resolution can be determined in the render engine's options. For example, in the options for VRay for Rhino , the Output Size determines the final render's resolution.