Method for measuring optical characteristics of an object situated in a measurement zone, the method comprising the following operations: - illumination of the object by means of a subnanosecond pulsed light source by emission of light rays in the direction towards the measurement zone, - acquisition of an image by modulated detection of light rays coming from the object following the illumination with the aid of means of acquisition of an image of the measurement zone which comprise an acquisition sensor (7, 10) comprising at least one pixel and adapted to acquire at least one measurement at at least one point or pixel, and with the aid of a control and acquisition unit which is synchronised with the light source and connected to the acquisition sensor (7, 10), the detection being modulated according to a temporal, continuous and non-sinusoidal acquisition modulation function G(t), the detection being modulated by acquisition modulation means interposed between the sensor (7, 10) and the measurement zone, the acquisition modulation means being controlled, at each acquisition, by the control and acquisition unit, which is also connected to the acquisition modulation means, the acquisition modulation means comprising an image intensifier and means for controlling the gain of the intensifier which are controlled by the control and acquisition unit, which is adapted to vary, during an acquisition period which runs from t 0 to t 0 +T, the gain of the intensifier in accordance with the acquisition modulation function G(t), which acquisition is carried out between two successive light pulses of the light source, and which acquisition, which has a duration T of between 5 nanoseconds and 10 nanoseconds, comprises, for each point or pixel of the image, the establishment of a value S corresponding to a quantity of light relative to an optical characteristic, such that S = ∫ t 0 t 0 + T G t H t dt where H(t) is a histogram of arrival times of photons at the point or pixel in question, and t 0 corresponds substantially to the time of emission of a pulse of the light source, and such that the quantity of light received at each pixel of the sensor (7, 10) corresponds to the value S, the acquisition modulation function G(t) being chosen to vary the gain of the intensifier from the following functions: - G k (t) = at k where a is a positive real number and k is an integer; - G c (t) = a'e -tc where a' is a positive real number and c is a real number; - G(t) is a wavelet. - illumination of the object by means of a subnanosecond pulsed light source by emission of light rays in the direction towards the measurement zone, - acquisition of an image by modulated detection of light rays coming from the object following the illumination with the aid of means of acquisition of an image of the measurement zone which comprise an acquisition sensor (7, 10) comprising at least one pixel and adapted to acquire at least one measurement at at least one point or pixel, and with the aid of a control and acquisition unit which is synchronised with the light source and connected to the acquisition sensor (7, 10), the detection being modulated according to a temporal, continuous and non-sinusoidal acquisition modulation function G(t), the detection being modulated by acquisition modulation means interposed between the sensor (7, 10) and the measurement zone, the acquisition modulation means being controlled, at each acquisition, by the control and acquisition unit, which is also connected to the acquisition modulation means, the acquisition modulation means comprising an image intensifier and means for controlling the gain of the intensifier which are controlled by the control and acquisition unit, which is adapted to vary, during an acquisition period which runs from t 0 to t 0 +T, the gain of the intensifier in accordance with the acquisition modulation function G(t), which acquisition is carried out between two successive light pulses of the light source, and which acquisition, which has a duration T of between 5 nanoseconds and 10 nanoseconds, comprises, for each point or pixel of the image, the establishment of a value S corresponding to a quantity of light relative to an optical characteristic, such that S = ∫ t 0 t 0 + T G t H t dt where H(t) is a histogram of arrival times of photons at the point or pixel in question, and t 0 corresponds substantially to the time of emission of a pulse of the light source, and such that the quantity of light received at each pixel of the sensor (7, 10) corresponds to the value S, the acquisition modulation function G(t) being chosen to vary the gain of the intensifier from the following functions: - G k (t) = at k where a is a positive real number and k is an integer; - G c (t) = a'e -tc where a' is a positive real number and c is a real number; - G(t) is a wavelet. where H(t) is a histogram of arrival times of photons at the point or pixel in question, and t 0 corresponds substantially to the time of emission of a pulse of the light source, and such that the quantity of light received at each pixel of the sensor (7, 10) corresponds to the value S, the acquisition modulation function G(t) being chosen to vary the gain of the intensifier from the following functions: - G k (t) = at k where a is a positive real number and k is an integer; - G c (t) = a'e -tc where a' is a positive real number and c is a real number; - G(t) is a wavelet. - G k (t) = at k where a is a positive real number and k is an integer; - G c (t) = a'e -tc where a' is a positive real number and c is a real number; - G(t) is a wavelet.