Emphasis Area

Use an emphasis area when the position of the workpiece cannot be determined correctly unless attention is paid to a small characteristic part of that workpiece.

To set an emphasis area in the model pattern, click the [Edit] button on the [Emphasis Area]. When an enlarged view of the model pattern appears on the image display control, fill the part where you want to set an emphasis area. Filling operation is similar to mask editing.

When an emphasis area is used to stabilize orientation calculation or prevent incorrect location, the target object fails to be found if the emphasis area cannot be found. In other words, if the emphasis area cannot be found, the target object goes undetected even when the object itself is detectable.

When [Enable] is unchecked, an emphasis area is ignored.

In the cases described below, specifying an emphasis area enables stable pattern location.

<1> When the position cannot be determined without paying attention to a small part
The position and orientation of both of the patterns shown in Fig.1 can be uniquely determined. Without the parts enclosed within the dotted-line boxes, however, they will end up being "geometries whose position or orientation cannot be determined". What is distinctive of these parts enclosed within the dotted-line boxes is that they are relatively small in comparison with the entire model pattern.
In such cases, the tool often finds the orientation or position incorrectly, because the pattern as a whole appears to match well, even though the part enclosed within the dotted-line box cannot be seen.
(i) Key groove in a circle
(ii) Line and small circle
Fig.1
Humans unconsciously pay attention to these small parts, while the GPM Locator Tool needs to be taught to do so. Such small parts that require special attention are called "emphasis areas". Teaching emphasis areas to the GPM Locator Tool makes it able to find position and orientation more accurately.
If the part specified as an emphasis area cannot be seen in the image, the pattern is not found, because the tool cannot verify that the correct pattern is found.
<2> When an incorrect pattern is found unless attention is paid to a small part
Suppose that you have two patterns of Figs.2(i) and (ii) mixed in the mage and want the tool to find only the pattern of Fig.2(ii). You teach the pattern of Fig.2(ii) as the model pattern. However, the pattern of Fig.2(i) has basically the same geometry, except for lack of the white circle, and thus gets a score of 90 points or higher, making it difficult for the tool to find only the pattern of Fig.2(ii). In such a case, specify the white circle, which is contained only in the pattern of Fig.2(ii), as an emphasis area. Doing so allows the tool to find only the pattern of Fig.2(ii) having the white circle more reliably.
If the part specified as an emphasis area cannot be seen in the image, the pattern is not found, because the tool cannot verify that the correct pattern is found.
If you want only the pattern of Fig.2(i) to be found, it is impossible for the Locator Tool alone to make this discrimination. In that case, you can use a sub-tool such as a Blob tool to detect the white circle along with a conditional execution tool to reject the found pattern if the white circle is present.
(i)
(ii)
Fig.2