This is what I want to do: Read in an image from disk (pngs in my case) Draw some shapes into it, like rectangles, ... Display the resulting image in my jupyter notebook and also save it back to file I'm currently using matplotlib for the drawing part. The issue: This process does not preserve resolution. The resulting png written to file is scaled by some random amount. As far as I understand, this is because matplotlib is using physical units and everything is dependent on screen size etc. That's a problem for me because I want to have pixel perfect drawing of the shapes and draw/save the image in the exact same resolution. I'm beginning to think that matplotlib might not be the right tool for what I want to do. Any advice? Below is the code I am currently using. import matplotlib.pyplot as plt import matplotlib.image as mpimg import matplotlib.patches as patches # Read the image. image_path = 'input_image.png' output_image_path = 'output_image.png' image = mpimg.imread(image_path) # Create a figure. fig, ax = plt.subplots(1) ax.axis('off') # Create a rectangle patch and add it. rect = patches.Rectangle((100, 100), 20, 20, linewidth=1, edgecolor='r', facecolor='none') ax.add_patch(rect) ax.imshow(image) # Save result. plt.savefig(output_image_path, bbox_inches='tight', pad_inches=0) # Input image: (1200x800) # Output image: (496x330) Continue reading...
