In this tutorial you will learn how to find a given configuration or pattern in a binary image by using the Hit-or-Miss transform (also known as Hit-and-Miss transform).
In this tutorial you will learn how to find a given configuration or pattern in a binary image by using the Hit-or-Miss transform (also known as Hit-and-Miss transform).
This transform is also the basis of more advanced morphological operations such as thinning or pruning.
This transform is also the basis of more advanced morphological operations such as thinning or pruning.
We will use the OpenCV function @ref cv::morphologyEx.
We will use the OpenCV function **morphologyEx()** .
Hit-or-Miss theory
Hit-or-Miss theory
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Morphological operators process images based on their shape. These operators apply one or more *structuring elements* to an input image to obtain the output image.
Morphological operators process images based on their shape. These operators apply one or more *structuring elements* to an input image to obtain the output image.
The two basic morphological operations are the *erosion* and the *dilation*. The combination of these two operations generate advanced morphological transformations such as *opening*, *closing*, or *top-hat* transform.
The two basic morphological operations are the *erosion* and the *dilation*. The combination of these two operations generate advanced morphological transformations such as *opening*, *closing*, or *top-hat* transform.
To know more about these and other basic morphological operations refer to previous tutorials @ref tutorial_erosion_dilatation "here" and @ref tutorial_opening_closing_hats "here".
To know more about these and other basic morphological operations refer to previous tutorials (@ref tutorial_erosion_dilatation "Eroding and Dilating") and (@ref tutorial_opening_closing_hats "More Morphology Transformations").
The Hit-or-Miss transformation is useful to find patterns in binary images. In particular, it finds those pixels whose neighbourhood matches the shape of a first structuring element \f$B_1\f$
The Hit-or-Miss transformation is useful to find patterns in binary images. In particular, it finds those pixels whose neighbourhood matches the shape of a first structuring element \f$B_1\f$
while not matching the shape of a second structuring element \f$B_2\f$ at the same time. Mathematically, the operation applied to an image \f$A\f$ can be expressed as follows:
while not matching the shape of a second structuring element \f$B_2\f$ at the same time. Mathematically, the operation applied to an image \f$A\f$ can be expressed as follows:
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@@ -43,11 +44,27 @@ You can see that the pattern is found in just one location within the image.
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@@ -43,11 +44,27 @@ You can see that the pattern is found in just one location within the image.
Code
Code
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The code corresponding to the previous example is shown below. You can also download it from
The code corresponding to the previous example is shown below.