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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).

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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.