1. Opencv Workshop
S2
Image processing Module (imgproc)
PS: The snippets of code are really basic just to show the concept, you can ameliorate it by adding
Some exception handling for example or make the values of thresholding more accurate..
it is just a hint
PS_2: I will put the image belong to template matching in the end of the presentation to test with it

2. Do You remember?
●
Imread
→ read image from file
Mat imread(const string& filename, int flags=1 )
●
namedWindows
→ Create an window
namedWindow(const string& winName, CV_WINDOW_AUTOSIZE )
●
ImShow
→ show the image in a windows
Void imshow(const string& winame, InputArray mat)

3. ●
Circle
→ void circle(Mat& img, Point center, int radius, const Scalar& color, int thickness=1, int
lineType=8, int
●
Line
→ void line(Mat& img, Point pt1, Point pt2, const Scalar& color, int thickness=1, int
lineType=8, int shift=0)
●
rectangle
→ void rectangle(Mat& img, Point pt1, Point pt2, const Scalar& color, int thickness=1, int
lineType=8, int shift=0)

5. Smoothing
Smoothing functions:
1-Mean Filter : void blur(InputArray src, OutputArray dst, Size ksize,
Point anchor=Point(-1,-1), int borderType=BORDER_DEFAULT )
2-Median Filter: void medianBlur(InputArray src, OutputArray dst, int ksize)
3-Gaussian Filter: void GaussianBlur(InputArray src, OutputArray dst,
Size ksize, double sigmaX, double sigmaY=0, int borderType=BORDER_DEFAULT )

6. snippet
Blur
Gaussian
Median

7. HoughLine Transform
void HoughLinesP(InputArray image, OutputArray lines, double rho, double theta,
int threshold, double minLineLength=0, double maxLineGap=0 )
HoughLineP

8. Edge Detection
void Canny(InputArray image, OutputArray edges, double threshold1,
double threshold2, int apertureSize=3, bool L2gradient=false )
Canny Edge Detection

9. Histogram Calculation
void calcHist(const Mat* images, int nimages, const int* channels, InputArray mask,
OutputArray hist, int dims, const int* histSize, const float** ranges, bool uniform=true,
bool accumulate=false )
Histogram

10. Template Matching
void matchTemplate(InputArray image, InputArray templ, OutputArray result, int
method)
Methods:
1- CV_TM_SQDIFF
2- CV_TM_SQDIFF_NORMED
3- CV_TM_CCORR
4- CV_TM_CCORR_NORMED
5- CV_TM_CCOEFF
6- CV_TM_CCOEFF_NORMED
void minMaxLoc(InputArray src, double* minVal, double* maxVal=0, Point*
minLoc=0, Point* maxLoc=0, InputArray mask=noArray())
Match template

11. template
img