Arrangements and method for provision of information indicative of intensity peak width for use with an image sensor for a 3d imaging system based on light triangulation

A method performed by one or more devices (205;

• 231;
• 331;
• 1000), for providing information indicative of an intensity peak width (371;
• 471;
• 571) of an intensity peak (363;
• 463;
• 563) along a pixel line (352-m) of pixels (366;
• 466;
• 566) comprising the intensity peak (363;
• 463;
• 563) and having intensity pixel values that are part of the intensity peak (363;
• 463;
• 563), wherein said pixels correspond to pixel elements of an image sensing area (351) of an image sensor (231;
• 331) and have attained their intensity pixel values from exposure of the image sensing area (351) as part of image sensing by the image sensor (231;
• 331) of light reflected from a surface, said intensity peak (363;
• 463;
• 563) being formed of such reflected light sensed by the image sensor (231;
• 331), wherein the method comprises:
• computing (601) a first value comprising a magnitude of a lower order Discrete Fourier Transform, DFT, coefficient (473;
• 573) regarding pixel intensity values for pixels (366;
• 466;
• 566) along the pixel line (352-m) that are comprising the intensity peak (363;
• 463;
• 563);
• computing (602) a second value comprising a magnitude of a another, higher order DFT coefficient (473;
• 573) regarding pixel intensity values for pixels (366;
• 466;
• 566) along the pixel line (352-m) that are comprising the intensity peak (363;
• 463;
• 563), said higher order being a higher order DFT coefficient (473;
• 573) than said lower order DFT coefficient (473;
• 573), and
• providing (603) said information indicative of the intensity peak width (371;
• 471;
• 571) based on said first and second values.