An infrared camera comprising a housing containing a pixel array , wherein the pixel array comprises: image pixels forming an image sensor arranged to receive infrared light from an image scene; a plurality of parasitic heat sensing pixels , a first of said parasitic heat sensing pixels being orientated in a different manner from a second of said parasitic heat sensing pixels such that the first and second parasitic heat sensing pixels receive infrared light from different portions of an interior surface of said housing ; a signal correction circuit configured to receive readings (P R ) from the plurality of parasitic heat sensing pixels , and to perform 2D signal correction on signals (I B ) captured by said image sensor based on said readings; characterised in that the infrared camera further comprises: a non-volatile memory storing a conversion matrix ( M Cpix ) for converting said readings (P R ) into correction values for performing said 2D signal correction, wherein said signal correction circuit is configured to convert said readings (P R ) into correction values by: converting, using a first conversion matrix ( M - 1 Clum ), said readings into estimates of the luminous flux received from each of a plurality of zones of a model of the interior surface of said housing, each zone being considered to have a uniform temperature; and converting, using a second conversion matrix ( M Cpix ), said estimates of the luminous flux received from each of said plurality of zones into the pixel correction values, wherein said model of the interior surface of said housing is a dome. image pixels forming an image sensor arranged to receive infrared light from an image scene; a plurality of parasitic heat sensing pixels , a first of said parasitic heat sensing pixels being orientated in a different manner from a second of said parasitic heat sensing pixels such that the first and second parasitic heat sensing pixels receive infrared light from different portions of an interior surface of said housing ; a signal correction circuit configured to receive readings (P R ) from the plurality of parasitic heat sensing pixels , and to perform 2D signal correction on signals (I B ) captured by said image sensor based on said readings; characterised in that the infrared camera further comprises: a non-volatile memory storing a conversion matrix ( M Cpix ) for converting said readings (P R ) into correction values for performing said 2D signal correction, wherein said signal correction circuit is configured to convert said readings (P R ) into correction values by: converting, using a first conversion matrix ( M - 1 Clum ), said readings into estimates of the luminous flux received from each of a plurality of zones of a model of the interior surface of said housing, each zone being considered to have a uniform temperature; and converting, using a second conversion matrix ( M Cpix ), said estimates of the luminous flux received from each of said plurality of zones into the pixel correction values, wherein said model of the interior surface of said housing is a dome. a non-volatile memory storing a conversion matrix ( M Cpix ) for converting said readings (P R ) into correction values for performing said 2D signal correction, wherein said signal correction circuit is configured to convert said readings (P R ) into correction values by: converting, using a first conversion matrix ( M - 1 Clum ), said readings into estimates of the luminous flux received from each of a plurality of zones of a model of the interior surface of said housing, each zone being considered to have a uniform temperature; and converting, using a second conversion matrix ( M Cpix ), said estimates of the luminous flux received from each of said plurality of zones into the pixel correction values, wherein said model of the interior surface of said housing is a dome. <EOS>