how to change window/level of displayed image

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Hi,

Default display of an arbitrary image is not always a best fit, as all grey levels are automatically displayed, image may appear as dark grey. Therefore before display, image should be "filtered" by setting to 0 all values below min val of that window, setting to max all values above that window, and re-sampling/re-interpolating all the values inside the window.

Is there any built-in function to change windowing of displayed image? If not - what function could be used prior display to apply the windowing filter above.

Thanks.