How to draw the area inside a contour using opencv? (the picture was exported from dxf file)

Question

I have a picture which has multiple mechanical components. They were exported directly from the dxf file using ezdxf. How can I divide them draw each one to an image separately? I have tried using contours, hierarchy = cv2.findContours(binary,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE) to draw them by plt by points in contours. However, the graph will be blurred. Is there any methods that can help me out? Below is the picture. Thanks in advance picture

Answer 1

I am considering that the input image is stored in the variable "inImage". This image is a binary image with only 0/255 values for each pixel. Use the code below to get each of the mechanical components on separate images.

# Finding the contours
Contours = cv2.findContours(inImage, cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_NONE)[-2]

ComponentImages = []
for Contour in Contours:
    # Getting the bounding box of the contour
    x, y, w, h = cv2.boundingRect(Contour)

    # Extracting the mechanical component from the original image
    img = inImage[y:y+h, x:x+w].copy()

    # Creating the mask image of the contour separately
    maskImg = np.zeros((h, w), dtype=np.uint8)
    cv2.drawContours(maskImg, [Contour], -1, 255, -1)

    # Performing bitwise operation to remove any part if not inside this contour
    img = cv2.bitwise_and(img, maskImg)

    # Storing this component image
    ComponentImages.append(img)

Finally, "ComponentImages" will store the images of each mechanical component.