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Selecting proper dpi (dots per inch) for image resolution should be done based on the content of the document and based on the use to of the digital image. Typically if the document has very small fonts then a higher image resolution would be recommended.
Once image resolution has been selected it is necessary to make sure if the camera is able to provide this resolution over the whole surface of the page. For a given image resolution, the larger is the page, the more pixels the camera should have.
Most customers would follow current state of the art recommended Standards & Best Practices for image resolution :
• For Preservation 600 dpi or higher
• For OCR 300 to 400 dpi
• For manuscripts 200 dpiThe Digitizing Line uses digital cameras from i2S Land of Vision. Current technologies offer much higher resolutions for linear CCD cameras than matrix CCD cameras. i2S Land of Vision is a world leader in precision linear CCD cameras.
These cameras may zoom in and out the document, in order to respectively increase or decrease image resolution. Depending on the camera, scanning resolution is selectable from 200 dpi to 800 dpi.
Linear CCD cameras require a scanning movement over the surface of the document. Therefore the scanning speed is a parameter for image resolution. For higher resolutions, scanning speed is slow, for lower resolutions scanning speed is fast.
