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Diffstat (limited to 'opencv.html.markdown')
| -rw-r--r-- | opencv.html.markdown | 69 |
1 files changed, 35 insertions, 34 deletions
diff --git a/opencv.html.markdown b/opencv.html.markdown index ff91d2a5..9a931bcb 100644 --- a/opencv.html.markdown +++ b/opencv.html.markdown @@ -7,9 +7,9 @@ contributors: --- ### Opencv -OpenCV (Open Source Computer Vision) is a library of programming functions mainly aimed at real-time computer vision. -Originally developed by Intel, it was later supported by Willow Garage then Itseez (which was later acquired by Intel). -Opencv currently supports wide variety of languages like, C++, Python, Java etc +OpenCV (Open Source Computer Vision) is a library of programming functions mainly aimed at real-time computer vision. +Originally developed by Intel, it was later supported by Willow Garage then Itseez (which was later acquired by Intel). +OpenCV currently supports wide variety of languages like, C++, Python, Java etc #### Installation Please refer to these articles for installation of OpenCV on your computer. @@ -27,14 +27,14 @@ img = cv2.imread('cat.jpg') # Displaying the image # imshow() function is used to display the image -cv2.imshow('Image',img) +cv2.imshow('Image', img) # Your first arguement is the title of the window and second parameter is image # If you are getting error, Object Type None, your image path may be wrong. Please recheck the pack to the image cv2.waitKey(0) # waitKey() is a keyboard binding function and takes arguement in milliseconds. For GUI events you MUST use waitKey() function. # Writing an image -cv2.imwrite('catgray.png',img) +cv2.imwrite('catgray.png', img) # first arguement is the file name and second is the image # Convert image to grayscale @@ -42,11 +42,11 @@ gray_image = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) # Capturing Video from Webcam cap = cv2.VideoCapture(0) -#0 is your camera, if you have multiple camera, you need to enter their id -while(True): +# 0 is your camera, if you have multiple camera, you need to enter their id +while True: # Capturing frame-by-frame _, frame = cap.read() - cv2.imshow('Frame',frame) + cv2.imshow('Frame', frame) # When user presses q -> quit if cv2.waitKey(1) & 0xFF == ord('q'): break @@ -55,59 +55,60 @@ cap.release() # Playing Video from file cap = cv2.VideoCapture('movie.mp4') -while(cap.isOpened()): +while cap.isOpened(): _, frame = cap.read() # Play the video in grayscale gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) - cv2.imshow('frame',gray) + cv2.imshow('frame', gray) if cv2.waitKey(1) & 0xFF == ord('q'): break cap.release() # Drawing The Line in OpenCV -# cv2.line(img,(x,y),(x1,y1),(color->r,g,b->0 to 255),thickness) -cv2.line(img,(0,0),(511,511),(255,0,0),5) +# cv2.line(img, (x,y), (x1,y1), (color->r,g,b->0 to 255), thickness) +cv2.line(img, (0, 0), (511, 511), (255, 0, 0), 5) # Drawing Rectangle -# cv2.rectangle(img,(x,y),(x1,y1),(color->r,g,b->0 to 255),thickness) +# cv2.rectangle(img, (x,y), (x1,y1), (color->r,g,b->0 to 255), thickness) # thickness = -1 used for filling the rectangle -cv2.rectangle(img,(384,0),(510,128),(0,255,0),3) +cv2.rectangle(img, (384, 0), (510, 128), (0, 255, 0), 3) # Drawing Circle -cv2.circle(img,(xCenter,yCenter), radius, (color->r,g,b->0 to 255), thickness) -cv2.circle(img,(200,90), 100, (0,0,255), -1) +# cv2.circle(img, (xCenter,yCenter), radius, (color->r,g,b->0 to 255), thickness) +cv2.circle(img, (200, 90), 100, (0, 0, 255), -1) # Drawing Ellipse -cv2.ellipse(img,(256,256),(100,50),0,0,180,255,-1) +cv2.ellipse(img, (256, 256), (100, 50), 0, 0, 180, 255, -1) # Adding Text On Images -cv2.putText(img,"Hello World!!!", (x,y), cv2.FONT_HERSHEY_SIMPLEX, 2, 255) +cv2.putText(img, "Hello World!!!", (x, y), cv2.FONT_HERSHEY_SIMPLEX, 2, 255) # Blending Images img1 = cv2.imread('cat.png') img2 = cv2.imread('openCV.jpg') -dst = cv2.addWeighted(img1,0.5,img2,0.5,0) +dst = cv2.addWeighted(img1, 0.5, img2, 0.5, 0) # Thresholding image # Binary Thresholding -_,thresImg = cv2.threshold(img,127,255,cv2.THRESH_BINARY) +_, thresImg = cv2.threshold(img, 127, 255, cv2.THRESH_BINARY) # Adaptive Thresholding -adapThres = cv2.adaptiveThreshold(img,255,cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY,11,2) +adapThres = cv2.adaptiveThreshold(img, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, 11, 2) # Blur Image # Gaussian Blur -blur = cv2.GaussianBlur(img,(5,5),0) +blur = cv2.GaussianBlur(img, (5, 5), 0) # Median Blur -medianBlur = cv2.medianBlur(img,5) +medianBlur = cv2.medianBlur(img, 5) # Canny Edge Detection -img = cv2.imread('cat.jpg',0) -edges = cv2.Canny(img,100,200) +img = cv2.imread('cat.jpg', 0) +edges = cv2.Canny(img, 100, 200) # Face Detection using Haar Cascades # Download Haar Cascades from https://github.com/opencv/opencv/blob/master/data/haarcascades/ import cv2 import numpy as np + face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml') eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml') @@ -115,21 +116,21 @@ img = cv2.imread('human.jpg') gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) faces = face_cascade.detectMultiScale(gray, 1.3, 5) -for (x,y,w,h) in faces: +for x, y, w, h in faces: # Draw a rectangle around detected face - cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) - roi_gray = gray[y:y+h, x:x+w] - roi_color = img[y:y+h, x:x+w] + cv2.rectangle(img, (x, y), (x + w, y + h), (255, 0, 0), 2) + roi_gray = gray[y : y + h, x : x + w] + roi_color = img[y : y + h, x : x + w] eyes = eye_cascade.detectMultiScale(roi_gray) - for (ex,ey,ew,eh) in eyes: + for ex, ey, ew, eh in eyes: # Draw a rectangle around detected eyes - cv2.rectangle(roi_color,(ex,ey),(ex+ew,ey+eh),(0,255,0),2) + cv2.rectangle(roi_color, (ex, ey), (ex + ew, ey + eh), (0, 255, 0), 2) -cv2.imshow('img',img) +cv2.imshow('img', img) cv2.waitKey(0) cv2.destroyAllWindows() -# destroyAllWindows() destroys all windows. +# destroyAllWindows() destroys all windows. # If you wish to destroy specific window pass the exact name of window you created. ``` @@ -139,7 +140,7 @@ cv2.destroyAllWindows() * OpenCV drawing Functions [https://docs.opencv.org/2.4/modules/core/doc/drawing_functions.html](https://docs.opencv.org/2.4/modules/core/doc/drawing_functions.html) * An up-to-date language reference can be found at [https://opencv.org](https://opencv.org) * Additional resources may be found at [https://en.wikipedia.org/wiki/OpenCV](https://en.wikipedia.org/wiki/OpenCV) -* Good OpenCv Tutorials +* Good OpenCV Tutorials * [https://realpython.com/python-opencv-color-spaces](https://realpython.com/python-opencv-color-spaces) * [https://pyimagesearch.com](https://pyimagesearch.com) * [https://www.learnopencv.com](https://www.learnopencv.com) |