Video presence systems are described that detect an area of interest (e.g., facial region) within captured image data and analyze the area of interest using known color information of the content currently being presented by a display, along with measured ambient light color information from a color sensor, to determine whether the area of interest (e.g., face) is currently illuminated by the display or whether the AOI is not affected by the display and instead only illuminated by the ambient light. Upon determining that the display casts color shade on the AOI, the video presence system pre-processes the image data of the detected area of interest to correct the color back to skin color under ambient light prior to performing general white balance correction.

The disclosed technology is directed to a light detecting apparatus used in an image acquiring apparatus. The image acquiring apparatus comprises a light receiving element that outputs a current according to a light amount of incident light. A current-voltage conversion circuit converts the current output from the light receiving element to a voltage signal. The current-voltage conversion circuit includes an operational amplifier and feedback resistance, feedback capacitance, and at least one diode that are connected in parallel between an inverting terminal and an output terminal of the operational amplifier. The diode is connected to have a forward direction from the inverting terminal toward the output terminal, and following conditional expressions are satisfied, G=R.sub.f B=1/(2R.sub.f(C.sub.f+C.sub.d/n)) and V.sub.pr>nV.sub.f>GI.sub.max.

Methods and systems for chroma reshaping are applied to images or video frames. The method comprises receiving at least one image or video frame. The color space of the at least one image or video frame is partitioned in M1M2M3 non-overlapping bins. For each bin it is determined whether it is a valid bin, for which the at least one image or video frame has at least one pixel with a color value falling within said bin. For each chroma channel, a required number of codewords is calculated for representing two color values in said valid bin that have consecutive codewords for the respective chroma channel without a noticeable difference. At least one content-aware chroma forward reshaping function is generated based on the calculated required numbers of codewords and applied to the at least one image or video frame.

The disclosed technology is directed to a light detecting apparatus used in an image acquiring apparatus. The image acquiring apparatus comprises a light receiving element that outputs a current according to a light amount of incident light. A current-voltage conversion circuit converts the current output from the light receiving element to a voltage signal. The current-voltage conversion circuit includes an operational amplifier and feedback resistance, feedback capacitance, and at least one diode that are connected in parallel between an inverting terminal and an output terminal of the operational amplifier. The diode is connected to have a forward direction from the inverting terminal toward the output terminal, and following conditional expressions are satisfied, G=R.sub.f B=1/(2R.sub.f(C.sub.f+C.sub.d/n)) and V.sub.pr>nV.sub.f>GI.sub.max.

Methods and systems for chroma reshaping are applied to images or video frames. The method comprises receiving at least one image or video frame. The color space of the at least one image or video frame is partitioned in M1?M2?M3 non-overlapping bins. For each bin it is determined whether it is a valid bin, for which the at least one image or video frame has at least one pixel with a color value falling within said bin. For each chroma channel, a required number of codewords is calculated for representing two color values in said valid bin that have consecutive codewords for the respective chroma channel without a noticeable difference. At least one content-aware chroma forward reshaping function is generated based on the calculated required numbers of codewords and applied to the at least one image or video frame.

An image processing apparatus includes: a gain calculating portion and a gain multiplication portion that perform signal enhancement with respect to an input image constituted by pixels having a plurality of color signals, with an intensity in accordance with signal values of each pixel, without changing a chroma and a hue; and a gamma correction portion that performs, for each pixel, tone conversion of a plurality of color signals that are subjected to signal enhancement, based on a weak gamma conversion curve in which a degree of gamma enhancement is weaker than in a basic gamma conversion curve which performs conversion such that a signal value of a halftone region at a time of outputting in a case where signal enhancement is not performed becomes a signal value in an appropriate output value range.