Tutorials of programming languages, frameworks, libraries, etc.
In this tutorial, you will learn how to mirror and flip an image using OpenCV (cv2) or Pillow (PIL). If you want to turn it by an angle instead, see how to rotate an image. OpenCV Pillow Full Example OpenCV Pillow Syntax OpenCV Parameters: Returns: Pillow Parameters: Returns: Parameters: Returns: References
This tutorial will show you how to rotate an image without cutting/cropping the sides of it using OpenCV (cv2) and Pillow (PIL). We also call this “rotation with bounding”. Rotate With Bounding For OpenCV, you need to first install imutils by: pip install imutils. The following code shows the image rotation by 45 degrees counterclockwise. […]
In this tutorial, you will learn how to rotate an image in OpenCV (cv2) and Pillow (PIL). 1. Rotate by 90, 180, or 270 Degrees For OpenCV, the function cv2.rotate lets you rotate the image only by 90, 180, or 270 degrees. 2. Rotate by Any Angle OpenCV Pillow Full Example OpenCV Pillow Syntax OpenCV […]
This tutorial will show you how to resize an image while preserving the aspect ratio in OpenCV (cv2) and Pillow (PIL), also, how to scale it by a scale ratio and resize it by a max height and width. If you don’t care about the aspect ratio, you can follow the previous tutorial. 1. Resize […]
In this part, I will show you the simple way to resize images (without keeping the aspect ratio) in OpenCV (cv2) and Pillow (PIL). If you want to resize an image while keeping the aspect ratio, read this tutorial. Resize Image Full Example Pillow OpenCV Syntax Pillow Parameters: Returns: OpenCV Parameters: Returns: References
Shape/size refers to the dimension of the image – width, height, and number of color channels. This tutorial will show you how to get the shape/size of an image in cv2 and PIL. Once you know the size, you can also resize and keep the aspect ratio. OpenCV Pillow Note: It is hard to get […]
In many circumstances, we need to convert a cv2 image to a PIL image (or PIL to cv2). Here, I will show you how to convert RGB/RGBA/grayscale images from cv2 to PIL or PIL to cv2. Since the color channels are ordered differently in PIL and cv2 images, we have to convert the color format […]
This tutorial will show you how to write/save images in jpg format and specify the image quality in both OpenCV (cv2) and Pillow (PIL). Specify JPEG Quality The recommended range for image quality is from 1 (worst) to 95 (best). Values above 95 should be avoided since 100 will disable portions of the JPEG compression […]
This part will show you the side-by-side comparisons of using OpenCV (cv2) and Pillow (PIL) to write/save images. Save an Image Full Example You might also want to learn how to read images using cv2 and PIL. To control the file size, you can also save a JPEG with a set quality. Pillow OpenCV Syntax […]
This tutorial will show you how to display/show an image using OpenCV (cv2) and Pillow (PIL). You might also want to learn how to read/open images using cv2 and PIL. Show Image Pillow OpenCV The cv2.waitKey(0) is used to prevent the window from being killed instantly. Full Example Pillow OpenCV Syntax Pillow Parameters: Returns: OpenCV […]