For example, start from row number 10 till row number 15 will give the height of the image. This will define the size of the newly created image. Now get the starting and ending index of the row and column. To show the image, use imshow() as below: cv2.imshow('Rotated Image', rotatedImage)Īfter running the above lines of code, you will have the following output:įirst, we need to import the cv2 module and read the image and extract the width and height of the image: import cv2 The rotated image is stored in the rotatedImage matrix. rotatedImage = cv2.warpAffine(img, rotationMatrix, (width, height)) To rotate the image, we have a cv2 method named wrapAffine which takes the original image, the rotation matrix of the image and the width and height of the image as arguments.
The next step is to rotate our image with the help of the rotation matrix.
Cv2 image resize code#
To get the rotation matrix of our image, the code will be: rotationMatrix = cv2.getRotationMatrix2D((width/2, height/2), 90. Here the center is the center point of rotation, the angle is the angle in degrees and scale is the scale property which makes the image fit on the screen. The syntax of getRotationMatrix2D() is: cv2.getRotationMatrix2D(center, angle, scale) To get the rotation matrix, we use the getRotationMatrix2D() method of cv2. Okay, now we have our image matrix and we want to get the rotation matrix. The shape attribute returns the height and width of the image matrix. To rotate this image, you need the width and the height of the image because you will use them in the rotation process as you will see later. Here we set the time to zero to show the window forever until we close it manually. The waitkey functions take time as an argument in milliseconds as a delay for the window to close. To display the image, you can use the imshow() method of cv2. All the time you are working with a NumPy array. It’s a NumPy array! That why image processing using OpenCV is so easy. The image is now treated as a matrix with rows and columns values stored in img.Īctually, if you check the type of the img, it will give you the following result: >print(type(img)) Now to read the image, use the imread() method of the cv2 module, specify the path to the image in the arguments and store the image in a variable as below: img = cv2.imread("pyimg.jpg") Let’s have some fun with some images!įirst of all, import the cv2 module. Now OpenCV is installed successfully and we are ready.
Cv2 image resize install#
If you have any other queries then you can contact us for getting more help.To install OpenCV on your system, run the following pip command: pip install opencv-python Hope you have liked this “how-to” tutorial. But I will prefer you to use cv2.resize() method for it. There are also other python modules that allow you to resize an image. You can verify the size of the image using the resized_img_with_scaling.shape. Resized_img_with_scaling = cv2.resize(img,(width,height)) Scaling allows you to adjust the image proportionally so that it looks good. If you look at the above-resized image, then you will see the image is not look good after the resizing. If you print the shape of the image then you will get the output as below. Output Resized Image of 600×500 dimension Then I will pass these dimensions inside the resize() method. Suppose I want to resize the image to 500×600 pixels. If you print the shape of the original image then you will get a width of 1280 and a height of 960. Output Sample image for implementing cv2 resize Step 3: Resize the image using cv2.resize() methodĪfter reading the image in step 2, in this section, I will resize the image using the resize() method. There is a method in OpenCV for it and that is the cv2.imread() method. Now before resizing the image you have to read the image. The statement %matplotlib inline allows you to display all the images in inline. Make sure that you also do all the work on it for a better understanding. Please note that I am executing all examples in the Jupyter notebook. The matplotlib module will be used for displaying the image. In our example, I am using the OpenCV module and the matplotlib python module.
The first and basic step is to import all the necessary libraries. Steps to Implement cv2 reize() method in python Step 1: Import all the necessary libraries
Cv2 image resize how to#
In this entire tutorial, you will know how to scale and resize an image using the OpenCV cv2 resize() method with step by step. Do you want to resize an image in python using cv2.
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