Image analysers from 1975 to 1990
Dr. Keith J. Morris
Above: The Cambridge Instruments Quantimet 720 hardware based image analyser with PDP11 minicomputer. This cost the MRC around £120,000 in 1972 prices. Despite many changes of ownership, PC based Quantimets are still being made by Leica in Cambridge
Left: The Seescan 256 software based image analyser - circa 1985
Above: CR-39 fission fragment track counting for lung microdosimetry studies
Above: A Seescan semi-automatic batch file
Right: A Fortran 77 data logging program running on a 286 IBM PC
Above left: A Fortran 77 program to set up raster scanning with the motorised XY stage used with the Seescan 256 image analyser
Above right: The motorised stage controller for the Reichert photomicroscope. This was originally integrated into the Quantimet 720 system..
The Seescan 256 had a pixel resolution of 256 x 256 for the digitised image, lower than the 500 lines of the Quantimet 720 it replaced. However the software driven system was far more flexible than the 720 (and had a smaller footprint). It was also significantly more user friendly and cost under £20,000 for the system. Seescan of Cambridge ceased trading around 1996 despite an impressive product line.
Although the Seescan had a low resolution it was ideal for use with microscopes where the magnification of the sample could be easily changed. A high resolution Newvicon B&W camera and monitor was added later to see more specimen detail. Having a standard 3.5" floppy disk, data could easily be transfered to an IBM 286 PC or the Norsk Data Mini computer in use at the MRC at that time. Although the Seescan could not control a motorised microscope stage, the old Quantimet Reichert microscope, stage and controller was set up as a stand alone system for manual movement via a joystick, or raster and random scans via a footswitch (see below).
Return to Magiscan Page