A method is provided for enhancing video images in a medical device. The method includes receiving a first image frame and a second image frame from one or more image sensors. The first image sub-blocks are generated by dividing the first image frame. At least one curve to the first image sub-blocks are associated based on one or more look-up tables. A target in at least one of the first image sub-blocks is identified. Second image sub-blocks are generated by dividing the second image frame. At least one curve is associated to the second image sub-blocks based on the one or more look-up tables. The target is identified in at least one of the second image sub-blocks. Histogram enhanced images of the target in the first image sub-blocks and the second image sub-blocks are generated. A video image stream is generated based on the histogram enhanced images of the target.