OpenCV - Remove text from image

Question

How do I remove text and markings from the below medical ultrasound image?

Answer 1

Thresholding to make a mask of the whiter areas and then inpainting will work for most cases in this image.

img = cv2.imread('ultrasound.png')
mask = cv2.threshold(img, 210, 255, cv2.THRESH_BINARY)[1][:,:,0]
dst = cv2.inpaint(img, mask, 7, cv2.INPAINT_NS)

Here's the mask:

Here's the inpainted image:

Notice the thresholding mask is not exact, and includes lighter regions where there are no letters. But more importantly, there is especially an issue if the mask does not include regions that need to be removed, such as the dark shadows of the crosses in the middle. Here's a zoom-in of that region.

The mask is just of the white region, and doesn't cover the dark areas. For problems like this where thresholding will not be enough, the mask can be adjusted manually. Here I take the original crosses in the mask and shift to also cover the shadows, and the inpainting is much better. (Similarly, if needed, the areas that shouldn't be included in the mask can be manually removed)

crosses = mask[235:267,290:320] | mask[233:265,288:318]
mask[235:267,290:318] = crosses
dst = cv2.inpaint(img, mask, 7, cv2.INPAINT_NS)