Edge detection: Difference between revisions

Revision as of 21:52, 11 May 2005

Revision as of 21:54, 11 May 2005

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If ''I''(''x'') represents the intensity of pixel ''x'', and ''I''′(''x'') represents the first derivative (intensity gradient) at pixel ''x'', we therefore find that:

:<math>I'(x)=-1\cdot I(x-1) + 0 \cdot I(x) + 1 \cdot I(x+1).\,</math>

''I''&prime;(''x'') = &minus;1&middot;''I''(''x''&nbsp;&minus;&nbsp;1)&nbsp;+&nbsp;0&middot;''I''(''x'')&nbsp;+&nbsp;1&middot;''I''(''x''&nbsp;+&nbsp;1)

For higher performance image processing, the 1st derivative can therefore be calculated (in 1D) by [[convolution|convolving]] the original data with a mask: