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HDevelop User's Manual

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114 CHAPTER 5. PROGRAM EXAMPLES<br />

Figure 5.19: Search areas for markings (left) and segmentation (right).<br />

ÅÒËÞ ¿¼<br />

×Ø×Ý×ØÑ ´³ÒØÒÛѳ¸ ³Ð׳µ<br />

ÖÑ ´ÅÓØÓÖÛݸ ³ÑÓØÓÖÛݳµ<br />

ÓÙÒØ×ÓÒ× ´ËÓÒ×½µ<br />

ÒÖÖÓÒ ´Ö¸ ÅÒËÞ¸ ÅÒËÞ¸ ³ÐÒ׳¸ ½¾¸ ½¾µ<br />

ÐÔÖÓÒ ´Ö¸ ÖÊÓ¸ ½¿¼¸ ½¼¸ ¼¸ ¼¾µ<br />

ÖÙÓÑÒ ´ÅÓØÓÖÛݸ ÖÊÓ¸ Å×µ<br />

×ÓÐÑÔ ´Å׸ ÖÒظ ³×ÙÑ׳¸ ¿µ<br />

ØÖ×ÓÐ ´ÖÒظ ÈÓÒØ׸ ¼¸ ¾µ<br />

ÐØÓÒÖØÒн ´ÈÓÒØ׸ ÊÓÒÐØÓÒ¸ ÅÒËÞ¸ ÅÒËÞµ<br />

ÖÙÓÑÒ ´ÅÓØÓÖÛݸ ÊÓÒÐØÓÒ¸ ËÒ×Öݵ<br />

ØÖ×ÓÐ ´ËÒ×Öݸ ËÒ׸ ½¼¸ ¾µ<br />

ÓÙÒØ×ÓÒ× ´ËÓÒ×¾µ<br />

ÌÑ ËÓÒ×¾¹ËÓÒ×½<br />

Ú×ÔÐÝ ´ËÒ×µ<br />

First you create a grid by using Ò Ö ÖÓÒ. It is reduced to the lower image half with<br />

ÐÔ ÖÓÒ. The operator ÖÙ ÓÑÒ creates an image containing this pattern as definition<br />

range. This image is passed to the operator ×ÓÐ ÑÔ. You obtain pixels with high<br />

gradient values using ØÖ×ÓÐ. These pixels are enlarged to the region of interest (ROI) by a<br />

dilation with a rectangular mask. Within this region another thresholding is performed. Correct<br />

road markings are equivalent to bright areas in the search window (ROI).<br />

The HALCON program needs an average of 20 ms on a standard Pentium. Notice that this is<br />

even possible under the following restrictions:<br />

1. Only standard operators have been used.<br />

2. Only encapsulated data structures have been used.<br />

3. Despite optimization the program is quite comprehensible.<br />

4. The program is very short.<br />

This example shows that you can write efficient programs even while using complex data struc-<br />

<strong>HDevelop</strong> / 2000-11-16

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