Abstract: A method is provided for evaluating quantity PQ representing a quality, as perceived by a recipient, of a signal OFx carrying data representing at least one stimulus intended to be produced on said recipient. The method includes a step of quantification of parameters Sqm and Tqm representing a spatial quality and a temporal quality of the signal, and a step of weighting during which a weighted product of the parameters Sqm and Tqm is computed and raised to a power C strictly below one. The method can be used to take account of a correlation that will be made by a person exposed to the stimulus between its spatial and temporal qualities, in applying an automatic technique in real time.

Abstract: A method is provided for evaluating quantity PQ representing a quality, as perceived by a recipient, of a signal OFx carrying data representing at least one stimulus intended to be produced on said recipient. The method includes a step of quantification of parameters Sqm and Tqm representing a spatial quality and a temporal quality of the signal, and a step of weighting during which a weighted product of the parameters Sqm and Tqm is computed and raised to a power C strictly below one. The method can be used to take account of a correlation that will be made by a person exposed to the stimulus between its spatial and temporal qualities, in applying an automatic technique in real time.

Abstract: A method and device for monitoring the quality of distributed digital images coded by blocks of pixels in which a false contour phenomenon may be generated when the image is reproduced. An image average for pixels represented by at least one luminance respectively chrominance components is calculated and a false contour effect on the basis of a criterion for discriminating the luminance or chrominance component difference between adjacent pixels of adjacent groups of pixels is detected in at least one reference direction of each current image. A visibility coefficient of at least one current image is calculated from the value of the image average speed vector and psycho-visual criteria relating to the existence of the false contour effect in the reference direction.

Abstract: A method and device for monitoring the quality of distributed digital images coded by blocks of pixels in which a false contour phenomenon may be generated when the image is reproduced. An image average for pixels represented by at least one luminance respectively chrominance components is calculated and a false contour effect on the basis of a criterion for discriminating the luminance or chrominance component difference between adjacent pixels of adjacent groups of pixels is detected in at least one reference direction of each current image. A visibility coefficient of at least one current image is calculated from the value of the image average speed vector and psycho-visual criteria relating to the existence of the false contour effect in the reference direction.