The present disclosure relates to a method performed by a deviation analyzing system (1) for black level drift assessment of a digital camera image sensor (21). The deviation analyzing system measures (1001) for pixels of an image captured by the image sensor, a respective luminance value and corresponding chromaticity value of each pixel. The deviation analyzing system further determines (1002) a respective average chromaticity value for differing luminance levels of the measured luminance values, based on for each luminance level averaging the corresponding measured chromaticity values. Moreover, the deviation analyzing system determines (1003), when the respective average chromaticity values of a range (4) of luminance levels indicate—to a predeterminable extent—chromaticity deviations (5) from the respective average chromaticity values (6) of other luminance levels (7), that a black level setting of the image sensor is drifted from a true black level.

The disclosure also relates to a deviation analyzing system in accordance with the foregoing, a digital camera comprising such a deviation analyzing system, and a respective corresponding computer program product and non-volatile computer readable storage medium.

An image signal processor that generates a display signal receives an input image signal having a first pedestal level from an image sensor, generates a first signal from the input image signal, the first signal including a second pedestal level, the second pedestal level being different from the first pedestal level and being determined in accordance with the first pedestal level and a processing gain of the image signal processor, generates a second signal having the second pedestal level by amplifying the first signal in accordance with the processing gain, generates a third signal having the second pedestal level by removing a noise signal from the second signal; and generates a fourth signal by subtracting the second pedestal level from the third signal.

The present disclosure relates to a method performed by a deviation analyzing system (1) for black level drift assessment of a digital camera image sensor (21). The deviation analyzing system measures (1001) for pixels of an image captured by the image sensor, a respective luminance value and corresponding chromaticity value of each pixel. The deviation analyzing system further determines (1002) a respective average chromaticity value for differing luminance levels of the measured luminance values, based on for each luminance level averaging the corresponding measured chromaticity values. Moreover, the deviation analyzing system determines (1003), when the respective average chromaticity values of a range (4) of luminance levels indicate—to a predeterminable extent—chromaticity deviations (5) from the respective average chromaticity values (6) of other luminance levels (7), that a black level setting of the image sensor is drifted from a true black level. The disclosure also relates to a deviation analyzing system in accordance with the foregoing, a digital camera comprising such a deviation analyzing system, and a respective corresponding computer program product and non-volatile computer readable storage medium.

An image signal processor that generates a display signal receives an input image signal having a first pedestal level from an image sensor, generates a first signal from the input image signal, the first signal including a second pedestal level, the second pedestal level being different from the first pedestal level and being determined in accordance with the first pedestal level and a processing gain of the image signal processor, generates a second signal having the second pedestal level by amplifying the first signal in accordance with the processing gain, generates a third signal having the second pedestal level by removing a noise signal from the second signal; and generates a fourth signal by subtracting the second pedestal level from the third signal.

An image signal processor that generates a display signal receives an input image signal having a first pedestal level from an image sensor, generates a first signal from the input image signal, the first signal including a second pedestal level, the second pedestal level being different from the first pedestal level and being determined in accordance with the first pedestal level and a processing gain of the image signal processor, generates a second signal having the second pedestal level by amplifying the first signal in accordance with the processing gain, generates a third signal having the second pedestal level by removing a noise signal from the second signal; and generates a fourth signal by subtracting the second pedestal level from the third signal.

An image signal processor that generates a display signal receives an input image signal having a first pedestal level from an image sensor, generates a first signal from the input image signal, the first signal including a second pedestal level, the second pedestal level being different from the first pedestal level and being determined in accordance with the first pedestal level and a processing gain of the image signal processor, generates a second signal having the second pedestal level by amplifying the first signal in accordance with the processing gain, generates a third signal having the second pedestal level by removing a noise signal from the second signal; and generates a fourth signal by subtracting the second pedestal level from the third signal.

In an imaging array having a plurality of pixel sensors arranged in a plurality of rows and columns, pixel data being read out on column lines of the array, a column line voltage clamp circuit for column lines of the array includes a master voltage clamp circuit coupled to provide a reference voltage clamp level on a reference node, and a slave voltage clamp circuit coupled to each column line in the imaging array, each slave voltage clamp circuit configured to clamp voltage on the column line to a column voltage clamp level derived from the reference voltage level.

In an imaging array having a plurality of pixel sensors arranged in a plurality of rows and columns, pixel data being read out on column lines of the array, a column line voltage clamp circuit for column lines of the array includes a master voltage clamp circuit coupled to provide a reference voltage clamp level on a reference node, and a slave voltage clamp circuit coupled to each column line in the imaging array, each slave voltage clamp circuit configured to clamp voltage on the column line to a column voltage clamp level derived from the reference voltage level.

Image processing devices and methods thereof use different color conversion data of an image obtained in a black-and-white mode under a low illuminance condition than that of an image obtained in a color mode.

Image processing devices and methods thereof use different color conversion data of an image obtained in a black-and-white mode under a low illuminance condition than that of an image obtained in a color mode.