在OpenCV Python中裁剪矩形

Question

I have an image like this

and I want to crop each book from the shelf. I started it with this code.

thresh = cv2.adaptiveThreshold(blur, 255, 1, 1, 11, 2)

cv2.imshow("Gray", gray)
cv2.waitKey(0)

cv2.imshow("Blurred", blur)
cv2.waitKey(0)

# detect edges in the image
edged = cv2.Canny(img, 10, 250)
cv2.imshow("Edged", edged)
cv2.waitKey(0)

# construct and apply a closing kernel to 'close' gaps between 'white'
# pixels
kernel = cv2.getStructuringElement(cv2.MORPH_RECT, (1, 6))
closed = cv2.morphologyEx(edged, cv2.MORPH_CLOSE, kernel)
cv2.imshow("Closed", closed)
cv2.waitKey(0)

# loop over the contours
for contour in contours:

    # peri = cv2.arcLength(contour, True)
    # approx = cv2.approxPolyDP(contour, 0.02 * peri, True)
    # r = cv2.boundingRect(contour)
    if len(contour) >= 4:
        index += 1
        x, y, w, h = cv2.boundingRect(contour)
        roi = img[y:y+h, x:x+w]
        # cv2.imwrite("a/" + "book - " + str(index) + '.jpg', roi)
        draw_contour = cv2.drawContours(img, [contour], -1, (255, 140, 240), 2)
        total += 1

print contour

cv2.imshow("Drawed Contour", img)
cv2.waitKey(0)

I created a bounding box in each of the books from the shelf, but unfortunately this gives me the output . I want only to draw a bounding box in the side/corner of the books and then crop it from the bounding box.

Answer 1

I don't think you can explicitly identify only books with this code but one quick improvement you can do in code is to draw contours which have area greater than some value. Following code snippet

 if len(contour) >= 4:
    index += 1
    x, y, w, h = cv2.boundingRect(contour)
    roi = img[y:y+h, x:x+w]
    # cv2.imwrite("a/" + "book - " + str(index) + '.jpg', roi)
    if cv2.contourArea(contour) > 200:
        draw_contour = cv2.drawContours(img, [contour], -1, (255, 140, 240), 2)
        total += 1