scanner

A scanner converts analog data into digital. It copies an electronic image of the document or object we scan on to the PC. We can then work on that image. Most scanners today are based on CCD technology, used for years in devices such as faxes. A desktop scanner has thousa

ds of CCD elements that convert light into an electrical charge. It converts the reflectance into analog voltage and then to digital values. Another technology Contact Image Sensor (CIS) was developed during the late 1990s. The CIS scanners are thinner, lighter, more efficient in terms of use of energy and cheap to manufacture. But when it comes to decent scan results, CIS scanners have not been able to produce good quality scans.

Scanners used to be bulky, expensive devices with average image quality. For high-res, we had to pay big money. Not anymore. Technology has given them a facelift and today we find sleek scanners that don’t cost a bomb and are efficient when it comes to details. A resolution of 600 x 1200 dpi, 48-bit color depth and USB 2.0 connectivity are just some of the features that have become standard in a budget scanner, costing around Rs 4-5K.

A. Selection Features  of a scanner

i. Resolution of the scanner

Resolution refers to the clarity and sharpness of an image. Higher the resolution, sharper would be the picture. While selecting a scanner pay attention to the Optical resolution of a scanner and not the Interpolated resolution. Optical resolution is the actual resolution at which the scanner will capture the image we’re scanning. Interpolated resolution is what the scanner uses to make the scanned image sharper. Interpolation is a process of enhancing a scanned image by filling more dots into it. The software goes through the scanned image and figures out the size and color of the dot. Based on that, it inserts more. This makes the image softer. While it’s a useful feature, we don’t choose one scanner over another purely on this. Till the late 1990s a typical scanner would have a resolution of 300 x 300 dpi, which has now shot up to 600 x 1200 dpi. This is quite decent for home use. Higher resolutions such as 1200 x 2400 dpi are better suited for design professionals.

This is the number of colors a scanner can recognize and scan. For home or office use, a 24-bit scanner will give very good results while scanning photographs etc. If we work extensively with graphics for publishing, consider a scanner with a higher color depth. Most of the scanners on the market now are 48-bit, which gives saturated color image with 281 trillion colors.

The scanner totally depends on the software to bring out its true colors. Apart from image editing and viewing software, one of the most important programs to have around is the OCR software.

iii. Easy connectivity to PC: As against the bygone era of parallel connectivity, the trend now is towards USB connectivity and we’ll find that most scanners these days have USB 2.0 connectivity. This means they’ll work faster.

iv. One-button scan: Most scanners now come with one-button scanning One-touch functionality has become a default with scanners that let us scan, copy, mail to Web or e-mail with just a push of a button.

B. Uses of a flat bed scanner

We can

·         Create a digital scrapbook of our choice

·         Scan pictures to send over mail to friends and family

·         Explore computer art—scan anything and make collages and original works of art

·         Make an exclusive e-book collection

·         Have fun with pictures—morph, animate them

·         Spruce up Website alive with scanned pictures and designs

·         Conserve old pictures—turn them digital and store them on CDs

·         Give the right impact with presentation—sprinkle it with relevant scanned pictures

·         Save time typing when copying from books—scan the text and use OCR to turn it into an editable form

·         Scan images for use in newsletters, design catalogues, product brochures, etc

·         Get a second opinion—scan past prescriptions and reports, and consult a scientist from another city, state or country over e-mail

·         Scan images for use in projects