Updated flags to OpenCV 4.0

[mhubii]

No description provided.

[mhubii]

hi @sourishg, sorry I know you are not actively maintaining this repo, however, people have started starring my fork for those updated OpenCV flags. Maybe if you could consider a merge, would be great!

I can confirm that this 4 year old PR still runs on Ubuntu 22.04 with OpenCV 4.5.4. Verified briefly via all examples

./calibrate \
    -w 9 \
    -h 6 \
    -n 27 \
    -s 0.02423 \
    -d "../calib_imgs/1/" \
    -i "left" \
    -o "cam_left.yml" \
    -e "jpg"

./calibrate \
    -w 9 \
    -h 6 \
    -n 27 \
    -s 0.02423 \
    -d "../calib_imgs/1/" \
    -i "right" \
    -o "cam_right.yml" \
    -e "jpg"

./calibrate_stereo \
    -n 27 \
    -u "cam_left.yml" \
    -v "cam_right.yml" \
    -L "../calib_imgs/1/" \
    -R "../calib_imgs/1/" \
    -l "left" \
    -r "right" \
    -o "cam_stereo.yml" \
    -e "jpg"

./undistort_rectify \
    -l "../calib_imgs/1/left1.jpg" \
    -r "../calib_imgs/1/right1.jpg" \
    -c "cam_stereo.yml" \
    -L "left.jpg" \
    -R "right.jpg"

[sourishg]

@mhubii thanks for this PR, I'm quite surprised that this repo is still useful. I'll go ahead and merge your changes. :)