Scanning for precision: Tarsus points the way forward

By definition, a scanner is the device used to capture images from sources like photographic prints, posters, magazine pages for computer editing and display. Typically, they feature software that allows for the modification or resizing of the captured image.

"I receive calls from clients complaining that they have a picture or an old photo that they want to scan, and their scanner cannot make it look any better," says Traci Maynard, IPG product manager at Tarsus Technologies, the value-add distribution arm of MB Technologies. "More often than not, it is a question of adjusting the scanner settings rather than the scanner itself being the problem."

Most of the new scanners feature one-button scanning capability, which is good enough for general projects. There may well be occasions, though, when the automatic settings on your scanner cannot make proper adjustments.

HP has identified how your scanner settings can be adjusted to get the best quality scan - whether it`s an old picture or a new one that needs to be scanned.

The scanner and monitor must be calibrated before use in order to ensure they are detecting and displaying colours correctly and consistently. The HP PrecisionScan software tool, which is shipped alongside many models of HP, can assist in performing this task. The HP PrecisionScan Pro software includes a powerful tool for adjusting the brightness and contrast of an image.

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Colour balance, saturation and brightness and contrast, are the three factors that affect the colour of an image.

Colour balance refers to the comparative amounts of red, green and blue. Too much of any one colour will give the image an unnatural cast.

Saturation is the amount of white or black added to a pure hue, to make it lighter or darker, respectively.

Brightness and contrast refers to the relative lightness/darkness of each colour and the number of different tones available.

Many image editors include tools with which to adjust these image qualities, but it is better to make corrections when scanning because the scanner has the original information to work from. HP`s PrecisionScan Pro allows small colour adjustments to be made before scanning.

Several other controls can also be used to adjust an image, either before or after scanning:

Sharpening can help better the quality fuzzy originals by increasing the contrast between pixels at boundaries in image areas, but the result is that everything on the image will be sharpened, including any dust or scratches. Threshold is a level the scanner uses to determine whether a pixel will be represented as black or white. This is used predominantly when scanning black and white line art, and the user can determine the threshold.

Luminance is related to saturation, but determines the amount of grey in a given hue. The brightness or darkness of an image can be adjusted by adjusting the luminance.

It is also important to consider the resolution being used to scan the image, as well as the file format to be used for the final output.

Maynard concludes: "The HP scanners include HP PrecisionScan Pro software which provides all the necessary tools to adjust settings to highlight and shadow and to set colours to your particular preference. The real benefit of the HP Scanners versus the `cheaper` dealer price equivalent is that the HP INCLUDES the OCR (Optical Character Recognition) software, which enables the computer to recognise printed characters. OCR involves photoscanning, analysis of the scanned-in image, and then translation of the character image into character codes for the purpose of manipulating or storing the image. HP is a real value for money buy as these software packages cost over R5 000. In addition, HP`s SJ7400C series can be used as a network scanner as it includes the PrecisionScan LAN scanning software for network sharing."