%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% NOTE ADDED Malcolm MacIver, March 10 2000 This resolution chart, and instructions for use, is by Dan Tomandl, University of Washington, dant@u.washington.edu I have resized the chart for printing on a large format printer to suit our needs. To print the chart on a standard printer, you may need to import it into a drawing program that can read PostScript, and resize it. The chart with the point-size resolution additions contains four blocks of dots, with varying contrasts, to help us assess the point resolution of our system (the water insects we image with infrared camera are close to points at the distance we observe them at). %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Resolution Chart Instructions This chart started out with video cameras in mind, but can be used totest about any image input or output device. Print it (it is apostscript file) or input it (scan it, frame grab it) from hard copy;note where the converging lines are no longer separate. The patterns it has are: a circle of wedges, two long wedges, a series of line widths, and a range of font sizes. One nice thing about postscript is that it scales with the capabilities ofthe device. This chart goes from 200 to over 5000 lines/image (from 35 toover 1000 lines/inch), whatever the device can do. Ideally your printedcopy will have enough resolution to adequately challenge your inputdevice; if not, and if your input device is a camera, you could just backoff until the the chart takes up only a fraction of the image. Of courseyou would then use that fraction to scale up the chart resolution numbers. To get this file to your printer, print it, or download it.One way to print it is with MS Word: select all, change style toPostscript, then print to a postscript printer. Interpretation example: let's say the lines blend together at the seconddashed circle (the first one inside the edge) in the upper half of thecircular test pattern. The resolution is 300 lines across the verticaldimension, 400 across the horizontal (in []) (the box and TVs have a 3 x4 aspect ratio), and 51 lines/inch (in {}). Note that numbers include*both* the black and white lines. Lines/inch is comparable to dots/inchor pixels/inch; divide by 2 to get line pairs/inch. After testing several scanners and printers I noticed a fairly consistentpattern: the lines merged at about half the dpi for thelaser printers I tested (from 300 to 1200 dpi). The scanners I testedpicked up line separations down to their dpi specs. I couldn't resist filling some unused space with more test patterns. Iput in some font sizes, then the line width progressions around the edges;finally the sparse line progression on the bottom (to get an uncrowdedview of small line widths) and the long wedges (which have the samewidths as the progression near them). Enjoy. Dan Tomandl; University of Washington; 3/94.Permission is hereby given to freely use this file. Comments andquestions may be addressed to dant@u.washington.edu Construction details: At res=200 lines .0285in/line; radius=2.04in ==>.8deg; 450 lines/circle; 225 dark wedges .8 deg each; 35.1 lines/in. RETMA resolution chart 1956 was used as a guide.