c++ - Opencv height/width of part of image -

c++ - Opencv height/width of part of image -

i've image 1 ![enter image description here][1]. non-black part expanded @ each iteration. so, after point, need enlarge final image non-black 1 can fit in. now, i'm doing find contour of non-black image,find bounding box of contours , check width/height of box. @ first time works, after iterations programme finds bounding box of size 1 (it seems doesn't find contour). problem be?

ps: programme mosaic video file, followed opencv tutorial find homography , other stuff.

edit sorry had remove images

just suggestion:

it's easier iterate through each element in matrix , record coordinates of uppermost, bottommost, leftmost , rightmost non-zero elements. these 4 corners of up-right bounding rectangle. of course of study not rectangle of minimum area enclosing non-zero pixels (not rotated rectangle), farther can used roi.

c++ opencv contour bounding-box image-stitching