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OpenCV is an Open Source Computer Vision Library in Python that provides numerous functions for image and video processing operations. It uses NumPy arrays to represent video and image data efficiently. In this article, we will learn how to handle mouse click events on video output using OpenCV's event handling system. This allows us to create interactive video applications that respond to user clicks. Mouse Events in OpenCV OpenCV provides several mouse event constants to detect different types of mouse interactions ? cv2.EVENT_LBUTTONDOWN: Left mouse button is pressed cv2.EVENT_RBUTTONDOWN: Right mouse button is pressed cv2.EVENT_MBUTTONDOWN: ... Read More
OpenCV is an Open Source Computer Vision Library in Python that provides numerous functions for image and video processing operations. When working with cameras, it's essential to verify if the camera is accessible before attempting to capture frames to avoid runtime errors. In this article, we will explore different methods to check if a camera is opened and accessible using OpenCV Python. The Problem: Unchecked Camera Access When we try to access a camera without checking its status, our program may encounter errors if the camera is unavailable, already in use, or malfunctioning. Example of Problematic ... Read More
The Python OpenCV library enables us to utilize a variety of image-processing tools, like image classification, face/object detection, tracking, and more. In this article, we will use Python list slicing or NumPy array slicing techniques to divide an image into equal parts, since OpenCV-Python uses NumPy arrays to store image data and pixel values. Input Output Scenarios Assuming we have an input image, in the output we will see the equally divided parts of the given image. Approach We will follow the below steps to divide the images into equal parts ? ... Read More
OpenCV Python is a powerful image processing library that uses NumPy arrays to store image data. This allows us to efficiently detect and count objects like white and black dots in images. The cv2.findContours() method is used for detecting objects in binary images. We'll use this method along with thresholding techniques to detect white and black dots ? Syntax cv2.findContours(image, mode, method[, contours[, hierarchy[, offset]]]) Parameters: image − 8-bit single-channel binary image mode − Contour retrieval mode method − Contour approximation method Approach Follow these steps to detect white and ... Read More
OpenCV is an Open Source Computer Vision Library in Python. It is one of the most popular image processing libraries and uses NumPy arrays to represent images. In this article, we will explore different methods to check if an image is empty or blank using OpenCV Python. Input-Output Scenarios We'll work with a blank input image and demonstrate how to programmatically detect whether an image is empty ? Input Image Expected Output Image is empty Method 1: Using Unique Pixel Count An empty image typically has very few unique ... Read More
A standard digital color image is represented by pixels, where each pixel is a combination of primary colors. A channel is a grayscale image that represents only one primary color component of a colored image. For example, an RGB image has three channels: red, green, and blue. Observe the below colored images to see how each channel looks separately: Below grayscale images are the representation of each channel of the RGB image. In this article, we will discuss how to split and merge channels of an image using Python OpenCV library. Splitting ... Read More
Top Hat and Black Hat Transforms are morphological operations used for feature extraction and enhancement in image processing. These operations help extract small details from images by analyzing structural differences between the original image and its morphological transformations. Top Hat Transform extracts bright small elements by computing the difference between the original image and its opening (top hat = image - opening). It highlights small bright features that are smaller than the structuring element. Black Hat Transform extracts dark small elements by computing the difference between the image's closing and the original image (black hat = closing - ... Read More
The coden is a Python library developed by Tanmay Earappa for handling secret codes and number base conversions. This module provides convenient functions to convert between binary, hexadecimal, and decimal number systems. Installation Install the coden module using pip − pip install coden Key Conversion Functions The coden module provides the following conversion functions − hex_to_bin(): Converts hexadecimal to binary hex_to_int(): Converts hexadecimal to decimal bin_to_hex(): Converts binary to hexadecimal bin_to_int(): Converts binary to decimal int_to_bin(): Converts decimal to binary int_to_hex(): Converts decimal to hexadecimal Hexadecimal to Binary Conversion ... Read More
Nested for loops execute repetitive code blocks, where an inner loop runs completely for each iteration of the outer loop. Python's map() function provides a functional programming approach to achieve similar results by applying functions to iterables. Understanding Nested For Loops A nested for loop structure contains one loop inside another ? for x in sequence: for y in sequence: # inner loop code # outer loop code Map Function Syntax map(function, iterable) Where: function: Function applied ... Read More
Dates can be in many formats like "2009/05/13 19:19:30", "May 13 2009 07:19PM", and "2009-05-13 19:19". Python provides several approaches to convert these unknown format strings into datetime objects using the datetime and dateutil modules. A Python datetime object contains complete information about date and time including year, month, day, hours, minutes, seconds, and time zones. This article shows how to convert unknown format date strings to datetime objects. Input-Output Example Here's what we want to achieve ? Input string (unknown format): 20050607T090650 Output Datetime object: 2005-06-07 09:06:50 Data type: Using datetime.strptime() ... Read More