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Image Acquisitionand Proces

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<strong>Image</strong> <strong>Proces</strong>sing 119<br />

Consider a grayscale image:<br />

125 122 111 110 107<br />

130 145 155 134 123<br />

131 156 159 141 136<br />

135 177 180 149 142<br />

150 202 213 170 160<br />

Perhaps you are interested only in intensity values that fall within a particular<br />

range, e.g., 140 and 175 inclusive. Performing a threshold operation on the previous<br />

image would yield the following image:<br />

0 0 0 0 0<br />

0 145 155 134 0<br />

0 156 159 141 0<br />

0 255 255 149 142<br />

150 255 255 170 160<br />

You can also perform a binary threshold by suppressing the intensities outside<br />

of the threshold interval to zero and highlighting those within the interval by setting<br />

their values to the maximum intensity values.<br />

I<br />

New<br />

Ï 0<br />

= Ì<br />

Ó<br />

255<br />

I < Range , I > Range<br />

Old Low Old High<br />

Range £ I £ Range<br />

Low Old High

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