Sharpness. To make easy the conversion to vector illustration is recommended that the photos are as sharp as possible. Less blur, less will cost interpret the picture and the illustration will be more detailed.

Megapixels. As more megapixels have an image, it will be clearer and sharper. In general the digital cameras make between 3 and 8 megapixel images. This will affect the quality of the picture and the file size.

Scanning the images. If your image isn’t in digital format and you scanning it, do it at a quality of 300dpi (if you can’t, set it at the largest that your scanner allow) to get as many details as possible of the image.

Size. Size matters. As a higher resolution have a picture, more detailed will be the final illustration because they will be more crisp.