Image-pickup signal processor and method of detecting flicker

A method of detecting flicker in an image-pickup signal processor for receiving image pickup signals that are output from a solid-state image pickup device and outputting the signals after predetermined signal processing, the method comprising the steps of:

• dividing an image into a plurality of flicker detection frames and detecting luminance data for each of the flicker detection frames;
• and
• extracting flicker data by taking the differences between the luminance data of a preceding frame and a current frame, and between the luminance data of the current frame and a following frame with respect to each of the flicker detection frames;
• and
• calculating a flicker frequency from the extracted flicker data, and
• calculating measurements for spaces between where a crest or trough of the extracted flicker data appears, and the measurements are converted into the flicker frequency.

A method of detecting flicker in an image-pickup signal processor for receiving image pickup signals that are output from a solid state image pickup device and outputting the signals after predetermined signal processing, the method comprising the steps of:

• dividing an image into a plurality of flicker detection frames and detecting luminance data for each of the flicker detection frames;
• and
• extracting flicker data by taking the differences between the luminance data of a preceding frame and a current frame, and between the luminance data of the current frame and a following frame with respect to each of the flicker detection frames;
• and
• calculating a flicker frequency from the extracted flicker data, and
• wherein a frame rate of the image pickup signals is controlled so as not to be synchronized with the flicker frequency.

A computer-readable recording medium having stored therein a flicker frequency determination program for detecting a flicker frequency of image pickup signals output from a solid-state image pickup device, the program comprising the steps of:

• extracting flicker data by taking differences between luminance data of a preceding flicker detection frame and a current flicker detection frame, and between luminance data of the current flicker detection frame and a following flicker detection frame with respect to each of a plurality of flicker detection frames that are formed by dividing an image picked up by the solid-state image pickup device;
• and
• calculating the flicker frequency from the extracted flicker data,
• wherein spaces between the flicker detection frames where a crest or trough of the extracted flicker data appears are measured and the measurements are converted into the flicker frequency.

A camera comprising:

• a solid state image pickup device;
• an image-pickup signal processor for receiving image pickup signals that are output from the solid-state image pickup device and outputting the signals after predetermined signal processing;
• and
• a microcomputer for detecting a flicker frequency in an image using a flicker frequency determination program,
• wherein the image is divided into a plurality of flicker detection frames,
• wherein luminance data for each of the flicker detection frames is detected and flicker data is extracted by taking differences between the luminance data of a preceding flicker detection frame and a current flicker detection frame, and between the luminance data of the current flicker detection frame and a following flicker detection frame with respect to each of the flicker detection frames, and
• wherein the flicker frequency is calculated from the extracted flicker data.