Drawing a cross on an image with OpenCV

Gireesha Devara
Updated on 30-May-2023 17:28:00
OpenCV is an Open Source Computer Vision Library in python. It provides numerous functions to perform various Image and video processing operations. The library uses the Numpy module to represent all the video frames and images as a ndarray type. It needs the numpy library, we need to make sure that the numpy module is also installed in our python interpreter. In this article, we will see different ways to draw a cross on an image using OpenCV Python. Let’s observe the input-output scenario to understand how to draw a cross on an image. Input Output Scenarios Assuming we have ... Read More

Draw Multiple Rectangles in Image using OpenCV Python

Gireesha Devara
Updated on 30-May-2023 16:31:22
OpenCV is an Open Source Computer Vision Library in python. It provides numerous functions to perform various Image and video processing operations. The library uses the Numpy module to represent all the video frames and images as a ndarray type. It needs the numpy library, we need to make sure that the numpy module is also installed in our python interpreter. In this article, we will see different ways to draw multiple rectangles in an image using OpenCV Python. To draw the rectangular shape on an image, Python OpenCV module provides a method called cv2.rectangle(). The cv2.rectangle() function The ... Read More

Removing Black Background and Make Transparent using OpenCV Python

Gireesha Devara
Updated on 30-May-2023 16:25:57
In digital images, Transparency is the functionality that supports transparent areas in an image or image layer. For image processing/image editing, background removing is allowing us to highlight the subject of the photo and create a transparent background to place the subject into various new designs and destinations. Certain image formats do not support transparency, for example, TIFF, PNG, and WebP graphics formats support transparency, whereas JPEGs have none. In this article, we will see how to remove the black background from an image to make it transparent using OpenCV Python. Like RGB channels, the alpha channel is used to ... Read More

Draw a rectangular shape and extract objects using Python's OpenCV

Gireesha Devara
Updated on 30-May-2023 16:21:35
OpenCV is an Open Source Computer Vision Library in python. It provides numerous functions to perform various Image and video processing operations. The library uses the Numpy module to represent all the video frames and images as a ndarray type. It needs the numpy library, we need to make sure that the numpy module is also installed in our python interpreter. In this article, we will see different ways to draw rectangular shapes and extract the object using python OpenCV. Drawing a Rectangle To draw the rectangular shape on an image, Python OpenCV module provides a method called cv2.rectangle(). This ... Read More

Display date and time in videos using OpenCV Python

Gireesha Devara
Updated on 30-May-2023 16:10:44
OpenCV is an Open Source Computer Vision Library in python. It provides numerous functions to perform various Image and video processing operations. The library uses the python Numpy module to represent all the video or image arrays as a ndarray type. It needs the numpy library, we need to make sure that the numpy module is also installed in our python interpreter. Displaying date and time in videos using OpenCV In live streaming/video processing applications sometimes we need to display the date and time on videos. To achieve this, we can use the python datetime module. The python datetime ... Read More

Click response on video output using Events in OpenCV and Python

Gireesha Devara
Updated on 30-May-2023 16:06:44
OpenCV is an Open Source Computer Vision Library in python. It provides numerous functions to perform various Image or video processing operations. The library uses the python Numpy module to represent all the video or image arrays as a ndarray type. In this article, we will see click responses on video output using events in the python OpenCV module. To identify which mouse event occurred on the video output. Here we will use the below mouse event − cv2.EVENT_LBUTTONDOWN: indicates the left button is pressed cv2.EVENT_RBUTTONDOWN: indicates the right button is pressed Also, we will use ... Read More

Check if the camera is opened or not using OpenCV Python

Gireesha Devara
Updated on 30-May-2023 16:04:12
OpenCV is an Open Source Computer Vision Library in python. It provides numerous functions to perform various Image or video processing operations. The library uses the python Numpy module to represent all the video or image arrays as a ndarray type. OpenCV-python needs the numpy library, we need to make sure that the numpy module is also installed in our python interpreter. In this article, we will see how to check if the camera is opened or not using OpenCV Python. Checking if the camera is opened We may not be sure about the status of the camera ... Read More

Dividing Images Into Equal Parts Using OpenCV Python

Gireesha Devara
Updated on 30-May-2023 16:01:14
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 the Numpy array to store the image data/pixel values. Input Output Scenarios Assuming we have an input image and in the output, we will see the equally divide parts of the given image. Approach We will follow the below steps to divide the images into equal parts. Load the image. Extract ... Read More

White and black dot detection using OpenCV Python

Gireesha Devara
Updated on 30-May-2023 15:58:07
OpenCV python is one of the image processing libraries in python and it uses the Numpy array to store the image data so that all the image arrays are represented as a ndarray type. The cv2.findContours() method in the python OpenCV module is used for detecting the objects in a binary image. In the article below, we will use this method to detect the White and Black dots (objects) in an image. Following is the syntax of this method – cv2.findContours(image, mode, method[, contours[, hierarchy[, offset]]]) Where, Image is an 8-bit single-channel image (binary image). Contours is ... Read More

Rotate image without cutting off sides using OpenCV Python

Gireesha Devara
Updated on 30-May-2023 15:55:23
Rotating an image is the most basic operation in image editing. The python OpenCV library provides the methods cv2.getRotationMatrix2D(), cv2.rotate() to do this task very easily. The cv2.rotate() will rotate the image in 0 or 90 or 180 or 270 angles only where as Cv2.getRotationMatrix2D() will rotate the image to any specified angle. In the article below, we will rotate the image without cropping or cutting off sides using OpenCV Python. To rotate an image using the cv2.getRotationMatrix2D() method then we need to follow below three steps − First, we need to get the centre of rotation. Next ... Read More
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