A very important detail for scanning on a desktop scanner is the focus of the film on the surface scanning, this is to avoid the lack of uniformity may be near the edges.
Dots per inch (dots per inch), It is a measure of the spatial resolution of an image. The higher resolution smaller pixel and increased noise.
For clinical dosimetry with Radiochromic film scanner it is recommended at a spatial resolution of 72 dpi.
Once the scanner provides an image file (each pixel has a value, on o off, white or black, 0-255 if greyscale, 8 bits, 12bits, etc) software or hardware compresses the image, if requested, and incorporates a header according to the type of format required. Examples are tiff, bpm, gif, cals, pcx, etc
For clinical dosimetry using recommended tif format.
The orientation (portrait or landscape) Radiochromic scanning of film is very important to maintain always the same, and it is recommended to do it in landscape mode always.