Low-light imaging system

An imaging unit for generating a low-light image, the imaging unit comprising a camera and a processing unit, wherein:

• the camera being configured to generate a first image comprising a set of pixels, each pixel of the set of pixels having a pixel colour defined by colour encoding values comprising a saturation value and a luma value, and
• the processing unit being configured to, for each pixel of the set of pixels:
• where the pixel colour corresponds to one of a first set of colours, modify the colour encoding values to reduce the saturation value of the pixel, and
• where the pixel colour corresponds to one of a second set of colours and where the luma value of the pixel is below a first threshold value, modify the colour encoding values to reduce the saturation value of the pixel, wherein the second set of colours consisting of at least one colour, and wherein the colours in the second set are not comprised in the first set of colours,
• where the pixel colour corresponds to one of the second set of colours and where the luma value of the pixel is equal to or above the first threshold value, preserve the saturation value of the pixel, and
• generate the low-light image in dependence on the modified colour encoding values of the first image.

A traffic monitoring system for generating a low-light image of a set of objects comprising at least one road and at least one traffic signalling light, the traffic monitoring system comprising an imaging unit configured to generate the low-light image of the set of objects in dependence on the modified colour encoding values of the first image;

• the imaging unit comprising a camera and a processing unit, wherein:
• the camera is configured to generate a first image comprising a set of pixels, each pixel of the set of pixels having a pixel colour defined by colour encoding values comprising a saturation value and a luma value, and
• the processing unit is configured to, for each pixel of the set of pixels:
• where the pixel colour corresponds to one of a first set of colours, modify the colour encoding values to reduce the saturation value of the pixel, and
• where the pixel colour corresponds to one of a second set of colours and where the luma value of the pixel is below a first threshold value, modify the colour encoding values to reduce the saturation value of the pixel, wherein the second set of colours consisting of at least one colour, and wherein the colours in the second set are not comprised in the first set of colours,
• where the pixel colour corresponds to one of the second set of colours and where the luma value of the pixel is equal to or above the first threshold value, preserve the saturation value of the pixel, and
• generate the low-light image in dependence on the modified colour encoding values of the first image.

A non-transitory computer readable medium having computer code instructions stored thereon which, when executed by a processing unit, are adapted to perform a method of generating a low-light image, the method comprising the steps of:

• capturing a first image comprising a set of pixels, each pixel of the set of pixels having a pixel colour defined by colour encoding values comprising a saturation value and a luma value, for each pixel of the set of pixels:
• where the pixel colour corresponds to one of a first set of colours, modifying the colour encoding values to reduce the saturation value of the pixel, and
• where the pixel colour corresponds to one of a second set of colours and where the luma value of the pixel is below a first threshold value, modifying the colour encoding values to reduce the saturation value of the pixel, wherein the second set of colours consisting of at least one colour, and wherein the colours in the second set are not comprised in the first set of colours,
• where the pixel colour corresponds to one of the second set of colours and where the luma value of the pixel is equal to or above the first threshold value, preserving the saturation value of the pixel,
• generating the low-light image in dependence on the modified colour encoding values of the first image.