HDevelop User's Manual

5.7. DEVICES 107
Figure 5.13: Resistors and capacitors (left) and ICs (right).
components. Unfortunately, they have become too large by the dilation. Another thresholding
for each connected component will detect the dark pixels of each IC. Finally, you can specify
the enclosing rectangles analogously to the resistors and the capacitors (see above).
ØÖ×ÓÐ ´ÁÒØÒ×Øݸ Ö¸ ¼¸ ¼µ
ÐØÓÒÖØÒн ´Ö¸ ÖÐظ ½¸ ½µ
ÓÒÒØÓÒ ´ÖÐظ ÁÄÖµ
ÒÒÐ× ´ÁÄÖ¸ ÁÒØÒ×Øݸ ÁÄÖÖݵ
ØÖ×ÓÐ ´ÁÄÖÖݸ Á×Ö¸ ¼¸ ¼µ
×ÔØÖÒ× ´Á×Ö¸ Á¸ ³ÖØÒо³µ
The right side of figure 5.13 shows the resulting ICs. We have to mention two aspects
about the program segment above. Here the operator ÒÒÐ× has been used instead
of ÖÙ ÓÑÒ. This is necessary as several regions have to be “supplied” with gray values.
The situation of previous programs was quite different: there the number of valid pixels of one
image has been restricted. From this follows the second point: here the operator ØÖ×ÓÐ
gets several images as input. 2 The thresholding is performed in every image. Thus you receive
as many regions as input images.
Finally, the segmentation of IC contacts has to be done. They are bright and small. Thus it
is easy to extract them using a dynamic thresholding (compare chapter 5.3). However, several
other tin elements on the board remain a problem, because they have to be distinguished from
the IC contacts. This can be done by restricting the search on a region of interest. IC contacts
may only appear either on the right or the left side of IC’s. The coarse region of interest is
defined by enlarging the IC regions with a following set subtraction. Then the result is resized
appropriately by using another dilation. Figure 5.14 shows the operator result on the left side.
Now you only have to intersect the result of the thresholding with the region of interest.
2 One matrix is shared by several iconic objects to reduce costs of memory and computation time.
HALCON 6.0