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IMAGE PROGRESSING FUNDAMENTALS

Part 1: Playing with the Pixels

by James Antonakos

Start ý Imaging 101 ý RLE Compressor Tool ý Adjusting the X-Y Resolution ý Adjusting the Z-Axis Resolution ý Simple Image Operations ý Run-Length Compression ý More to Come ý Sources and PDF

ADJUSTING THE X-Y RESOLUTION

The x-y resolution of the image affects the quality of the image. Lower resolution results in lower quality, as demonstrated in Photos 2aýc. The blocky chunks in Photo 2a make it hard to see whatýs going on in the image. If you squint your eyes or move the image farther away, the hard edges of the blocks will blur slightly (a quick and dirty low-pass filter) and the image will actually look a little better. Try this method with Photos 2a and b.

a)	b)	c)
Photos 2aýcýThese three images show how the x-y resolution of an image affects its quality. The resolutions are (a) 16 ý 16, (b) 32 ý 32, and (c) 64 ý 64.

Some applications may not require a high x-y resolution. For example, if you are pointing a camera at a panel of indicator lights, low resolution will be enough to tell if lights are on or off, although you will not see any details of the lights themselves. Other applications, such as optical character recognition, require high x-y resolution.

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