Filtering method and device for processing a time signal by temporal noise reduction

A filtering device for reducing Gaussian noise and flicker noise in a time signal, comprising:

• one or more processors;
• and
• one or more memories storing one or more programs comprising instructions that, when executed by the one or more processors, cause the one or more processors to:
• receive, at a current instant k, a current value of the time signal output from a Time-of-Flight (ToF) sensor configured to generate a depth data map, the current value of the time signal comprising at least one data map, each data map being associated with a physical parameter;
• for each physical parameter, provide J candidate variables, with J≥2, each candidate variable being associated with an occurrence score and with a confidence interval;
• determine a current value of each confidence interval at the current instant k;
• select a candidate variable when the current value of the time signal is included in a current value of a corresponding confidence interval;
• update a current value of occurrence scores based on the selection;
• when the current value of the time signal is only included in the current value of the confidence interval associated with a selected candidate variable, update a current value of the selected candidate variable by averaging a precedent value of the selected candidate variable at a preceding instant k−1 with the current value of the time signal;
• and
• provide a filtered value of the time signal at the current instant k as being equal to the current value of the candidate variable having a highest occurrence score.

A system for reducing Gaussian noise and flicker noise in a time signal, comprising:

• a sensor device configured to output a current value of the time signal at successive instants, the current value of the time signal comprising at least one data map, each data map being associated with a physical parameter;
• and
• a filtering device coupled to the sensor device, the filtering device comprising:
• one or more processors;
• and
• one or more memories storing one or more programs comprising instructions that, when executed by the one or more processors, cause the one or more processors to:
• receive, at a current instant k, the current value of the time signal from the sensor device;
• for each physical parameter, provide J candidate variables, with J>2, each candidate variable being associated with an occurrence score and with a confidence interval;
• determine a current value of each confidence interval at the current instant k;
• select a candidate variable when the current value of the time signal is included in a current value of a corresponding confidence interval;
• update a current value of occurrence scores based on the selection;
• when the current value of the time signal is only included in the current value of the confidence interval associated with a selected candidate variable, update a current value of the selected candidate variable by averaging a precedent value of the selected candidate variable at a preceding instant k−1 with the current value of the time signal;
• and
• provide a filtered value of the time signal at the current instant k as being equal to the current value of the candidate variable having a highest occurrence score.