All pictures are not created equal; some are just better suited for digitizing than others. For example, an image with a large section of clear blue sky may look like a good candidate in its original form, but a picture with less sky showing may be a better choice. Here's why: The sky is actually composed of dozens of shades of blue. The conversion software that converts this 16 million color image (24 bits) to 256 colors (8 bits) will probably reduce these dozens of blues to four or five shades. The result is a striped or blotchy sky.
A good image enhancement program will let you blend this handful of colors so that the blotches are barely noticeable, but remember, every extra step adds more time (cost) to the overall production process. Making a good choice will save touch-up time later in production. This is especially true when the application's runtime palette size is limited to 16 or 256 colors.
Another important characteristic of the original image is its physical size. If the original image is too small, you may have to enlarge and distort the image. If the original image is too large, there may be too much detail and you'll have to shrink it. The best size is between 3-by-5 and 8-by-10.
Here are some other important factors to consider when choosing images:
| Images to use have . . . | Images to avoid have . . . |
| Consistent lighting with balanced contrast | Hundreds of wildly varying colors | |
| A moderate number of bold, mixed colors | Deep, dark shadows | |
| Image components that look good blended | High contrast such as bright whites or blacks | |
| Low level of detail | Large sections of a solid color (such as sky) | |
| Human or complex subjects with simple backgrounds , | ||
The texture of the original will affect the final quality. Use high-quality prints whenever possible.