Automatic control of visual parameters in video processing
View Patent ↗Embodiments of the invention are directed to a system and method for controlling visual parameters of a capturing device to minimize clipping and saturation according to predefined parameters. The method may include processing pixel values of a current input frame of a received video signal captured by a capturing device; accumulating processing results of the current input frame to processing results of one or more previous input frames and calculating a desired dynamic range based on pre-determined user parameters. The processing may further include checking if the accumulated results are within the desired dynamic range and determining if adjustment is desired. If the accumulated results are not within the desired dynamic range, adjusting visual parameters for a subsequent input frame, by controlling the capturing device and if the accumulated results are within the desired dynamic range maintaining current visual parameters of the current input frame for the subsequent input frame.
1. A method for processing video signals comprising:
processing pixel values for a current input frame of a received video signal, wherein the signal is captured by a capturing device;
generating an accumulated histogram using the pixel values of the current frame together with pixel values of one or more previous input frames;
calculating a calculated low-clipping threshold and a calculated high-saturation threshold based on the accumulated histogram and according to predetermined parameters for a threshold calculation;
calculating a desired dynamic range based on predetermined user parameters for a dynamic range calculation and determining a desired low sensitivity area and a desired high sensitivity area;
checking if the accumulated histogram is within the desired dynamic range and determining if adjustment is desired by identifying a location of the calculated low-clipping threshold relative to the desired low sensitivity area and a location of the calculated high-saturation threshold relative to the desired high sensitivity area;
adjusting visual parameters for a following input frame by controlling the capturing device if the accumulated histogram is not within the desired dynamic range; and
maintaining current visual parameters for the following input frame if the accumulated histogram is within the desired dynamic range.
2. The method of claim 1 , further comprising:
setting the predetermined parameters prior to processing pixel values of the current input frame of the received video signal.
3. The method of claim 1 , further comprising:
determining whether a scene had changed between the current frame and a previous frame and performing a reset operation.
4. The method of claim 1 , wherein adjusting the visual parameters for the following input frame comprises updating the visual parameters of the capturing device.
5. The method of claim 1 , wherein adjusting the visual parameters for the following input frame comprises increasing the frequency of updating the visual parameters of the capturing device.
6. The method of claim 1 , wherein maintaining the current visual parameters for the following input frame comprises decreasing the frequency of updating the visual parameters.
7. A system for video signal processing comprising:
a capturing device to capture a current input frame of a video signal;
a frame receiver to receive a digital representation of the current input frame from the capturing device;
a frame calculator to process pixel values of the current input frame and to generate an accumulated histogram for the pixel values of the current frame together with pixel values of one or more previous input frames;
a frame analyzer to calculate a desired dynamic range and to determine a desired low-sensitivity area and a desired high-sensitivity area based on pre-determined user parameters for dynamic range calculation, to calculate a calculated low-clipping threshold and a calculated high-saturation threshold based on the accumulated histogram and according to predetermined parameters for a threshold calculation and to check if the accumulated histogram is within the desired dynamic range by identifying a location of the calculated low-clipping threshold relative to the low-sensitivity area and the location of the calculated high-saturation threshold relative to the high-sensitivity area; and
a controller to determined if adjustment is desired, to adjust visual parameters for a following input frame by controlling the capturing device if the accumulated histogram is not within the desired dynamic range and to maintain current visual parameters for the following input frame if the accumulated histogram is within the desired dynamic range.
8. The system of claim 7 , further comprising:
a memory unit to store the predetermined parameters.
9. The system of claim 7 , wherein the controller is to update the visual parameters of the capturing device for capturing the following input frame if the accumulated histogram is not in a desired sensitivity range.
10. The system of claim 9 , wherein the controller is to increase the frequency of updating the visual parameters.
11. The system of claim 7 , wherein the controller is to maintain the current visual parameters of the capturing device for capturing the following input frame and to decrease the frequency of updating the visual parameters if the accumulated histogram is in a desired sensitivity area.
12. An article comprising a non-transitory computer-storage medium having stored thereon instructions that, when executed by a processing platform, result in:
processing pixel values for a current input frame of a received video signal, wherein the signal is captured by a capturing device;
generating an accumulated histogram using the pixel values of the current frame and pixel values of one or more previous input frames;
calculating a calculated low-clipping threshold and a calculated high-saturation threshold based on the accumulated histogram and according to predetermined parameters for a threshold calculation;
calculating a desired dynamic range based on predetermined user parameters for a dynamic range calculation and determining a desired low sensitivity area and a desired high sensitivity area;
checking if the accumulated histogram is within the desired dynamic range and determining if adjustment is desired by identifying a location of the calculated low-clipping threshold relative to the desired low sensitivity area and a location of the calculated high-saturation threshold relative to the desired high sensitivity area;
adjusting visual parameters for a following input frame by controlling the capturing device if the accumulated histogram is not within the desired dynamic range; and
maintaining current visual parameters for the following input frame if the accumulated histogram is within the desired dynamic range.