Abstract: The method comprises acquiring a bidimensional image formed by a plurality of dots, characterized by a brightness value; dividing the bidimensional image into a plurality of image regions, each formed by a respective first number of dots; for each of the image regions, determining a first quantity correlated to the brightness variation intensity of each dot with respect to adjacent dots; for each image region, determining at least one second quantity correlated to the brightness variation direction of each dot with respect to adjacent dots; and determining any presence and type of a code in each of the image regions, on the basis of the determined quantities. These quantities typically comprise the contrast level of the image region, obtained by adding the gradient variation intensity of all contrast dots of the image region and directionality of the image region, obtained by calculating the gradient variation direction for all dots and searching for the prevalent direction or directions.

Abstract: Apparatus for measuring the amount of fuel in a tank comprises a capacitive probe whose capacitance is a function of the fuel level in the tank, an electronic circuit including a monostable multivibrator to which the probe is connected as a timing capacitor and a trigger source for repetitively triggering the monostable multivibrator to provide a series of output signals whose duty cycle is a function of probe capacitance, and a display responsive to the pulses or a signal derived from them to indicate the amount of fuel in the tank.