HelpBrowserSettings -> {opt_1 -> val_1, opt_2 -> val_2, ...} is a global option that specifies settings for the legacy Help Browser.
HitMissTransform[image, ker] gives the hit-and-miss transform of image with respect to the composite structuring element ker.HitMissTransform[image, {ker_1, ker_2, ...}] ...
HoldForm[expr] prints as the expression expr, with expr maintained in an unevaluated form.
HoldRest is an attribute which specifies that all but the first argument to a function are to be maintained in an unevaluated form.
ImageAlign[image_1, image_2] returns a version of image_2 that is aligned with image_1.
ImageCapture[] opens a graphical user interface for capturing images from connected cameras.
ImageDifference[image_1, image_2] gives an image in which each pixel is the absolute difference of the corresponding pixels in image_1 and image_2.
ImageResolution is an option for Export, Rasterize, and related functions that specifies at what resolution bitmap images should be rendered.
ImageSizeAction is an option for Pane and related constructs that specifies what to do if the specified ImageSize setting does not match the size of the contents.
ImageSizeMultipliers is an option that specifies how much smaller to render graphics that appear within other constructs.