Python Learning

  Python – Colour Detection using Pandas & OpenCV What is Colour Detection? Colour detection is the process of detecting the name of any color. Simple isn’t it? Well, for humans this is an extremely easy task but for computers, it is not straightforward. Human eyes and brains work together to translate light into color. Light receptors that are present in our eyes transmit the signal to the brain. Our brain then recognizes the color. Since childhood, we have mapped certain lights with their color names. We will be using the somewhat same strategy to detect color names. Prerequisites Before starting with this Python project with source code, you should be familiar with the computer vision library of Python that is  OpenCV  and  Pandas . OpenCV, Pandas, and numpy are the Python packages that are necessary for this project in Python. To install them, simply run this pip command in your terminal: pip install opencv-python numpy pandas Run Python File The beginner Python project is now

  How to Detect Shapes in Images in Python using OpenCV import numpy as np import matplotlib.pyplot as plt import cv2 import sys # read the image from arguments image = cv2.imread( r'G:\PARAS\anuradha.png' ) # convert to grayscale grayscale = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) # perform edge detection edges = cv2.Canny(grayscale, 30 , 100 ) # detect lines in the image using hough lines technique lines = cv2.HoughLinesP(edges, 1 , np.pi/ 180 , 60 , np.array([]), 50 , 5 ) # iterate over the output lines and draw them for line in lines: for x1, y1, x2, y2 in line: cv2.line(image, (x1, y1), (x2, y2), color =( 20 , 220 , 20 ), thickness = 3 ) # show the image plt.imshow(image) plt.show()

  Text Detection and Extraction using OpenCV and OCR Applying OCR: Loop through each contour and take the x and y coordinates and the width and height using the function  cv2.boundingRect() . Then draw a rectangle in the image using the function cv2.rectangle() with the help of obtained x and y coordinates and the width and height. There are 5 parameters in the cv2.rectangle(), the first parameter specifies the input image, followed by the x and y coordinates (starting coordinates of the rectangle), the ending coordinates of the rectangle which is (x+w, y+h), the boundary color for the rectangle in RGB value and the size of the boundary. Now crop the rectangular region and then pass it to the tesseract to extract the text from the image. Then we open the created text file in append mode to append the obtained text and close the file Finding Contours: cv2.findContours()  is used to find contours in the dilated image. There are three arguments in cv.findContours(): the source image, the

In the end we will see, it can be concluded that Tesseract is perfect for scanning clean documents and you can easily convert  the image’s text from OCR to word,  pdf to word,  or  to any other required format.  It has pretty high accuracy and font variability. This is very useful in case of institutions where a lot of documentation is involved such as government offices, hospitals, educational institutes, etc. In the current release 4.0, Tesseract supports OCR based deep learning that is significantly more accurate. You can access the code file and input image  here  to create your own OCR task. Try replicating this task and achieve the desirable results, happy coding! Coding Here, I will use the following sample receipt image: First part is image thresholding. Following is the code that you can use for thresholding: pytesseract.pytesseract.tesseract_cmd = 'C:/Program Files/Tesseract-OCR/tesseract.exe' # your path may be different For Windows Only 1 - You need to have Tesser