How to remove blank space from cropped image om opencv?-CodePudding

I am trying to crop a specific part of a frame in opencv to get a cropped image of the detections from mobilenet ssd model. The code to crop the image is like this

for box_id in boxes_ids:
                        x,y,w,h,id = box_id
                        crop=frame[y:h,x:w]
                        cv2.imshow("d",crop)
                        cv2.waitKey(5)

This code is producing a blank space towards the right of all the images that I extract :

Please tell me how can i fix this.

CodePudding user response：

try using Pillow that helps

def trim(im, color):
    bg = Image.new(im.mode, im.size, color)
    diff = ImageChops.difference(im, bg)
    diff = ImageChops.add(diff, diff)
    bbox = diff.getbbox()
    if bbox:
        return im.crop(bbox)

This function will probably take it out, just be carefull that this will only work if the segment of image has consistent pixels

CodePudding user response：

as said before in the comments, there is a minimum window width, and smaller crops will be drawn on some neutral background.

but maybe it's more intuitive to draw the crop into an empty image, conserving its original position:

for box_id in boxes_ids:
    x,y,w,h,id = box_id
    draw = np.zeros(frame.shape, np.uint8)    
    draw[y:h,x:w] = frame[y:h,x:w]
    cv2.imshow("d",draw)
    cv2.waitKey(5)