Query on NDVI image

[Aman Dalmia]

Hi All,

I have an ndvi image, let say http://www.sunrise21.org.au/userfiles/ndvi.jpg

I need to make a border around the dense red area. How can I do this.

Thanks,

-Aman

[Michael Beyeler]

Hi Aman,

Here's a possible outline:

• Convert to HSV.
• Find the distribution (range) of HSV values of pixels in the red zone.
• Use this range to make a mask that only contains the red pixels (using inRange).
• Find the contours of all red blobs.
• For each contour, find the outermost pixels (x_min, x_max, y_min, y_max). Use as boundaries for rectangles.
• Draw a rectangle in the original image.

Best,

Michael