Process and apparatus for providing data indicative of the shape of leaf-like article

Claim 1

A process for deriving digital information indicative of the outer contour of a leaf-like article and of the holes which it may comprise, said holes having to be taken into consideration for the use of the article when their dimensions exceed a determined threshold, from a sampled analog video signal composed of image lines and representing the image of the article placed on a support, said process comprising the steps of comparing the video signal, for each image dot or sample, with a threshold and coding the dot "1" or "0" according to the result of the comparison; detecting the transitions in the digital signal thus obtained; coding this digital signal as a "leaf" signal or word when the signal is in state "0" (or "1") and as a "support" word when the signal is in state "1" (or "0") and when it relates to a hole; comparing with the above-mentioned threshold, expressed by a number n 1 of image dots, the number n of dots coded "1" (or "0") which follow one another, firstly in a line X (direction Y), then in consecutive lines X, X+1, etc. (direction X); converting the "support" signals if n÷n 1 , into "flaw" signals and transmitting them unchanged if n<n 1 ; storing solely the signals preceding a transition, together with corresponding position data Y, by writing them line by line as said lines appear; reading the stored information in an order opposite the order of writing, whereby line X+1 is read before line X; transmitting the signals other than the "support" signals unaltered, and processing the "support" signals as follows: if a "support" signal of a line X is located in the vicinity of a "flaw" signal present in previously read line X+1, it is converted into a "flaw" signal, and if this is not the case, it is not transmitted.

Claim 3

An apparatus for delivering digital information indicative of the outer contour of a leaf-like article and and of holes which it may include, said apparatus comprising: means for delivering a sampled analog video signal in the form of successive image lines, a comparator for comparing the video signal with a threshold and delivers a digital signal according to said comparison, a coder connected to receive an input signal from the comparator for delivering a pulse when transition occurs in the input signal and for delivering a digital signal or words according to the value of the input signal and the transitions, a processing circuit for receiving the digital signal from the comparator and counting the number of consecutive "1"s (or "0"s) in one line X and in successive lines X, X+1, etc. and delivering "support" or "flaw" words depending on whether said number is lower than or higher than a value n 1 , a switching circuit connected to the coder and to the processing circuit for substituting the words from the processing circuit for the corresponding words from the coder, a memory of which the directions of read-in and read-out are opposite and in which the signals from the switching circuit are entered together with their positions Y under the control of the transition pulses from the coder, an output circuit for receiving the stored "support" signals and converting a "support" signal located in line X in the vicinity of at least one "flaw" signal located in the line X+1 into a "flaw" signal and without passing the "flaw" signals from said circuit and the other signals from said memory.

Claim 4

An apparatus for delivering digital information indicative of the outer contour of a leaf-like article and and of holes which it may include, said apparatus comprising: means for delivering a sampled analog video signal in the form of successive image lines, a comparator for comparing the video signal with a threshold and delivers a digital signal according to said comparison, a coder connected to receive an input signal from the comparator for delivering a pulse when transition occurs in the input signal and for delivering a digital signal or words according to the value of the input signal and the transitions, a processing circuit for receiving the digital signal from the comparator and counting the number of consecutive "1"s (or "0"s) in one line X and in successive lines X, X+1, etc. and delivering "support" or "flaw" words depending on whether said number is lower than or higher than a value n 1 , a switching circuit connected to the coder and to the processing circuit for substituting the words from the processing circuit for the corresponding words from the coder, a memory of which the directions of read-in and read-out are opposite and in which the signals from the switching circuit are entered together with their positions Y under the control of the transition pulses from the coder, an output circuit for receiving the stored "support" signals and converting a "support" signal located in line X in the vicinity of at least one "flaw" signal located in the line X+1 into a "flaw" signal and without passing the "flaw" signals from said circuit and the other signals from said memory.