Method and apparatus for real time identification and correction of pixel defects for image sensor arrays

A method for correcting pixel image data, comprising:

• a) obtaining at least three lines of image data containing signal values for a corresponding number of lines of an image obtained from a pixel array in an image sensor;
• b) comparing a signal value of a pixel to be tested from among the at least three lines of signal values with the respective signal values of at least eight pixels from among the at least three lines of signal values and which surround the tested pixel, having the eight surrounding pixels the same color type as the tested pixel;
• c) if the signal value of the tested pixel is larger than all of the signal values for the eight surrounding pixels, redefining the signal value of the tested pixel to be equal to the maximum signal value from among the signal values of the eight surrounding pixels;
• d) if the signal value of the tested pixel is smaller than all of the signal values for the eight surrounding pixels, redefining the signal value of the tested pixel to be equal to the minimum signal value from among the signal values of the eight surrounding pixels.

A method for correcting pixel image data, comprising:

• writing at least three lines of image data containing signal values for a corresponding number of lines of an image obtained from a pixel array in an image sensor, into a plurality of memory banks;
• sequentially inputting the image data from the memory banks into a plurality of sets of shift registers;
• comparing a signal value of a pixel to be tested in the shift registers with the signal values of at least eight surrounding pixels in the shift registers and which are of a same color filter type as the tested pixel;
• if the signal value of the pixel being tested is larger than all of the signal values of the eight surrounding pixels, correcting the signal value of the pixel being tested to be equal to the largest signal value from among the eight surrounding pixels;
• and
• if the signal value of the pixel being tested is smaller than all of the signal values of the eight surrounding pixels, correcting the signal value of the pixel being tested to be equal to the smallest signal value from among the eight surrounding pixels.

A method for correcting pixel image data comprising:

• a) obtaining at least three lines of image data containing signal values for a corresponding number of lines of image data of an image obtained from a pixel array in an image sensor;
• b) comparing a signal value of a pixel to be tested from among the at least three lines of image data with the respective signal values of at least eight pixels from among the at least three lines of image data and which surround the tested pixel, the eight surrounding pixels having the same color type as the tested pixel;
• and
• c) replacing the signal value of the tested pixel with the maximum signal value from among the signal values of the eight surrounding pixels if the signal value of the tested pixel is larger than all of the signal values for the eight surrounding pixels.

A method for correcting image data due to defective pixels in an image sensor array, comprising:

• a) obtaining at least three lines of image data containing signal values for a corresponding number of lines of image data of an image obtained from a pixel array in an image sensor;
• b) comparing a signal value of a pixel to be tested from among the at least three lines of image data with the respective signal values of at least eight pixels from among the at least three lines of image data and which surround the tested pixel, the eight surrounding pixels having the same color type as the tested pixel;
• and
• c) replacing the signal value of the tested pixel with the minimum signal value from among the signal values of the eight surrounding pixels if the signal value of the tested pixel is smaller than all of the signal values for the eight surrounding pixels.

An image processing apparatus comprising:

• an image sensing unit for obtaining an image and outputting an image signal which includes pixel image data containing signal values for each line of the image;
• an image processor for processing the image signal;
• and
• a controller for controlling the image sensing unit and the image processor, and
• wherein the image processor includes a defective pixel data correction circuit which receives the pixel image data and compares the signal value of a tested pixel with the signal values of at least eight pixels surrounding the tested pixel in the image, and which, if the signal value of the tested pixel is larger than all of the signal values of the eight surrounding pixels, replaces the signal value of the tested pixel with the largest signal value from among the eight surrounding pixels, and which, if the signal value of the tested pixel is smaller than all of the signal values of the eight surrounding pixels, replaces the signal value of the tested pixel with the smallest signal value from among the eight surrounding pixels.

A processing system, comprising:

• a processor for receiving an processing image data;
• and
• an image data generator for supplying image data to the processor, the image data generator comprising
• an image sensing unit for obtaining an image and outputting an image signal,
• an image processor for processing the image signal, and
• a controller for controlling the image sensing unit and the image processor,
• wherein the image processor includes a defective pixel data correction circuit which receives the pixel image data and compares the signal value of a tested pixel with the signal values of at least eight pixels surrounding the tested pixel in the image, and which, if the signal value of the tested pixel is larger than all of the signal values of the eight surrounding pixels, replaces the signal value of the tested pixel with the largest signal value from among the eight surrounding pixels, and which, if the signal value of the tested pixel is smaller than all of the signal values of the eight surrounding pixels, replaces the signal value of the tested pixel with the smallest signal value from among the eight surrounding pixels.