How can I define two tones in a grayscale image

Hi

I have an ultrasound image with lots of gray tones. I want to threshold the image by defining two of its tones. The higher intensity (white tone) and the lowest intensity (darkest gray tone). All other tones in the middle should be eliminated.

How can I do this?

Thanks

Answer 1

[Jan]

You cannot eliminate colors in a gray-scale image, but only set them to another value.

img(img > 67 & img < 128) = 0;

Here all gray scale values between 68 and 127 are set to 0.

[Sulaymon Eshkabilov]

(+1) = Short and very efficient solution!

[Stelios Fanourakis]

"Here all gray scale values between 64 and 127 are set to 0."

You mean values between 68 and 127 are set to 0

[Jan]

@Stelios: Correct. This was a typo.