Video frame grabber comprising analog video signals analysis system

Claim 1

A method to determine in a video frame grabber an optimal time delay to generate time delayed synchronisation signals corresponding to video signals, for triggering sampling clock signals within each video line, comprising the following steps: (a) generating the video signals having fast transients; (b) setting a time delay to generate said time delayed synchronisation signals; (c) setting a first sampling delay for said sampling clock signals with respect to said time delayed synchronisation signals; (d) sampling said video signals at a predetermined frequency of said sampling clock signals to obtain first digital image signals; (e) setting a second sampling delay for said sampling clock signals with respect to said time delayed synchronisation signals; (f) sampling said video signals at said predetermined frequency of said sampling clock signals to obtain second digital image signals; (g) computing a first difference score between said first and second digital image signals; (h) computing a second difference score between said first digital image signals and said second digital image signals, offset by one sample; (i) repeating steps (c) to (f) for at least two first sampling delay settings; (j) selecting a critical first sampling delay setting, the first sampling delay setting corresponding with the first and second difference score indicative of a sample offset; (k) selecting said optimal time delay such that the critical first sampling delay setting is most different from a sampling delay setting at which said video signals are digitized.

Claim 2

A method to determine in a video frame grabber an optimal time delay to generate time delayed synchronisation signals corresponding to video signals, for triggering sampling clock signals within each video line, comprising the following steps: (a) generating the video signals having fast transients; (b) setting a time delay to generate said time delayed synchronisation signals; (c) setting a first sampling delay for said sampling clock signals with respect to said time delayed synchronisation signals; (d) sampling said video signals at a predetermined frequency of said sampling clock signals to obtain first digital image signals; (e) setting a second sampling delay for said sampling clock signals with respect to said time delayed synchronisation signals; (f) sampling said video signals at said predetermined frequency of said sampling clock signals to obtain second digital image signals; (g) computing a first difference score between said first and second digital image signals; (h) computing a second difference score between said first digital image signals and said second digital image signals, offset by one sample; (i) repeating steps (c) to (f) for at least two first sampling delay settings; (j) selecting a critical first sampling delay setting, the first sampling delay setting corresponding with the first and second difference score indicative of a sample offset; (k) selecting said optimal time delay such that the critical first sampling delay setting is most different from a sampling delay setting at which said video signals are digitized.