Quick Fix: Utilize OpenCV and Matplotlib functions to convert the figure to a NumPy array, then use cv2.imshow() to display.
The Problem:
In matplotlib, we can create various plots and save them as images. However, sometimes it can be useful to convert a matplotlib figure directly to a cv2 image, without having to save it first. This can be beneficial for displaying the figure using OpenCV’s imshow function. By converting the matplotlib figure to a cv2 image, we can take advantage of OpenCV’s image processing capabilities and display the plot using OpenCV’s visualization tools.
The Solutions:
Solution 1: Convert Matplotlib Figure to Numpy Array
To convert a Matplotlib figure to a cv2 image without saving it first, you can utilize the following steps:
Initialize a Matplotlib figure and axes.
Plot your desired data on the axes.
Call the `fig.canvas.draw()` method to render the figure.
Convert the figure to a Numpy array using `np.array(fig.canvas.renderer.buffer_rgba())`.
Convert the Numpy array from RGBA to BGR color space using `cv2.cvtColor(img_plot, cv2.COLOR_RGBA2BGR)`.
Display the converted image using `cv2.imshow(‘Image’, img_plot)`.
Wait for a key press to terminate the image window with `cv2.waitKey(0)`.
By following these steps, you can directly display a Matplotlib figure in OpenCV without the need to save it as an external image file.
Q&A
Is it possible to use cv2.imshow to display matplotlib plot without saving it first?
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Yes, you can convert matplotlib figure to a NumPy array and display it with cv2.imshow().
What steps are required to convert a matplotlib figure to a NumPy array?
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You can create a figure, draw it, and then convert the figure’s canvas to a NumPy array using np.array(fig.canvas.renderer.buffer_rgba()).
How do you display a matplotlib figure in OpenCV?
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You can use cv2.imshow to display a matplotlib figure after converting it to a NumPy array and converting the color format from RGBA to BGR.
Video Explanation:
The following video, titled "Image Processing with OpenCV and Python - YouTube", provides additional insights and in-depth exploration related to the topics discussed in this post.
In this Introduction to Image Processing with Python, kaggle grandmaster Rob Mulla shows how to work with image data in python! Python image ...
