Power control technique using error distribution analysis for ultrasound imaging displays

In this paper, a new power control technique based on clipped error distribution is proposed for portable ultrasound imaging displays. To reduce the display power consumption, the backlight dimming is used to select the optimal point between the power reduction of a backlight and the high image quality. In this case, the clipped error, i.e., the saturation error for pixels exceeding the maximum expressible gray level, should be considered. Conventional algorithms do not consider the clipped error distribution, which is the spatial distribution of pixels with the clipped error in a frame image when the power consumption is reduced. Therefore, it degrades the image quality in the medical display. On the other hand, the proposed algorithm calculates statistical values for clipped error distribution by analyzing the image characteristics. Hence, it can avoid degradation of the image quality by concentrating the pixels with clipped errors in a small region. In addition, the proposed algorithm uses a sampling technique, which only uses selected pixels based on the pre-defined sampling pattern, to reduce the computation time. Experimental results show that the proposed algorithm can improve the image quality in terms of peak signal-to-noise ratio by up to 7.063 dB (23.49%) while reducing the computation time by up to 0.451 µs (17.18%) using a sampling technique.