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.