Patent ID: 11967002
Assignee: AXIS AB
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A method performed by an image-processing device, the method comprising:
obtaining a digital colour image having pixels, and
applying a linear random function (f) to a respective colour vector representing colour components of a respective pixel of the digital colour image to obtain an anonym ized monochrome colour image,
wherein the linear random function (f) varies over the pixels of the digital colour image,
wherein the linear random function (f) further is dependent on at least one random parameter,
wherein the linear random function (f) is a polynomial of a pixel location within the digital colour image, and
wherein applying the linear random function (f) comprises one of:
projecting the colour vector with a linear random projection function (f1) onto a one-dimensional colour component, or
rotating the colour vector with a linear random rotation function (f2), thereby obtaining a rotated colour vector, and projecting the rotated colour vector with a projection function onto the one-dimensional colour component.