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THR2 Thresholding and Scaling Accelerator
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The THR2 Board can serve as a production facility
for bulk conversion of color or grayscale images to binary images. This
may occur in color imaging systems which need to output to
printers or fax modems. It may occur in systems where a color
orientation is taken for archiving, but where OCR engines require binary images. The VST-1000 chips operate at up to 30
million pixels per second and (in an embedded design) may be
operated in parallel to achieves pixel rates as high as 80
million pixels per second or more. The THR2 Board
is capable of keeping them fed with fresh grayscale data from
host memory over the PCI bus at burst rates of up to 132 Mbytes
per second. Output binary pixels are collected into 32 bit long
words and buffered up for burst transfers back into a host memory
output buffer at up to 132 Mbyte per second rates. Up-scaling hardware is included in the THR2 to cover the common
requirement to create binary images at up to two times the resolution
of the source color or grayscale images. This produces smoother, better-looking
binary images which produce superior OCR results. The VST-1000 chips have a despeckling
capability built in. This permits removal of small, isolated
black objects on the background of the binary image and of small
white voids in the interior of characters or other black regions.
While the size limits are programmable, the despeckler may remove
all black speckles up to 4 by 4 pixels in size and all white
regions up to 3 by 3 pixels in size. In addition, the connectivity
(used to determine whether an object is isolated or not) may be
programmed to be either 4-way or 8-way, allowing a better job at
achieving the desired retention or elimination of halftone
patterns. |
Seeing Like the Eye Sees for Quality Images The human eye extracts edge information at high resolution in the first stage of vision and pattern recognition. The edges in a scene at high resolution provide the location information upon which all further processing is based. Luminance (brightness or tonality or shading) and chrominance (color) information are handled at lower resolutions. The bitonal images upon which much of the document imaging business traditionally has been based give a practical confirmation of these facts; bitonal images have high spatial resolution, but low tonal resolution or tonality. In fact, they only have two tones or shades: full white and full black. The revolutionary edge thresholding method used by the Picture Elements VST-1000 integrated circuit permits the creation of very high definition binary images. These images are characterized by accurate stroke width rendition, exceptional, carefully-chiselled clarity of fine detail and superior reproduction of the broader, fuzzy edges seen in carbon copies and overnight express waybills. |
To Buy The THR2Price: $1995 USD United States
Japan
Asia/Pacific Outside Japan
Europe
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Kodak 4500 Color Scanner Owners Your Kodak 4500 scanner and its ISIS and TWAIN drivers already support the THR2 Board!
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Picture Elements is a trademark of Picture Elements, Inc. |