A method performed by a people distinguishing system for i, in an image, distinguishing human beings in a crowd, said method comprising: identifying by detecting and classifying objects, one or more detected objects classified as human beings in an image derived from a thermal camera adapted to capture a scene in an essentially forward-looking angle considered eye level of people and/or from slightly there above; the method being characterized by : identifying at least a first grouping of adjoining pixels in said image , not comprised in the one or more detected human beings , having an intensity within a predeterminable intensity range; determining a grouping pixel area of said at least first grouping in said image by computer vision techniques and/or image processing; determining for at least a first vertical position (y expected ) of said grouping pixel area in said image , based on head size reference data , an expected pixel area (x expected ) size and form of a human head at said at least first vertical position (y expected ), wherein said head size reference data is represented by data indicative of a relationship between vertical positions (y) in the image and corresponding expected pixel areas (x expected ) size and form of a human head; comparing at least a portion resembling a human head of said grouping pixel area with said expected head pixel area (x expected ) for said at least first vertical position (y expected ); and determining that said at least first grouping comprises at least a first overlapping human being , when at least a first comparison resulting from said comparing exceeds a predeterminable conformity threshold. identifying by detecting and classifying objects, one or more detected objects classified as human beings in an image derived from a thermal camera adapted to capture a scene in an essentially forward-looking angle considered eye level of people and/or from slightly there above; the method being characterized by : identifying at least a first grouping of adjoining pixels in said image , not comprised in the one or more detected human beings , having an intensity within a predeterminable intensity range; determining a grouping pixel area of said at least first grouping in said image by computer vision techniques and/or image processing; determining for at least a first vertical position (y expected ) of said grouping pixel area in said image , based on head size reference data , an expected pixel area (x expected ) size and form of a human head at said at least first vertical position (y expected ), wherein said head size reference data is represented by data indicative of a relationship between vertical positions (y) in the image and corresponding expected pixel areas (x expected ) size and form of a human head; comparing at least a portion resembling a human head of said grouping pixel area with said expected head pixel area (x expected ) for said at least first vertical position (y expected ); and determining that said at least first grouping comprises at least a first overlapping human being , when at least a first comparison resulting from said comparing exceeds a predeterminable conformity threshold. <EOS>