Method for reading a two-dimensional matrix of pixels and device for implementing such a method
AssigneeCommissariat a l'Energie Atomique
InventorArnaud Verdant
Life of this patent
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Abstract
The invention relates to a method for reading a two-dimensional matrix of pixels of an image sensor, the matrix being organized in blocks of pixels forming macropixels, each macropixel being readable independently of one another in high resolution mode and/or in low resolution mode. The method includes the steps of, during the selection of the high resolution readout mode for a macropixel, in reading and storing the values of the pixels thereof, in order to define a reference macropixel, and during the subsequent high resolution readout cycles of this macropixel, in forming the difference between the read values of the pixels thereof and the values of the corresponding pixels of the reference macropixel.
Claims5
A method for detecting and tracking moving objects using a two-dimensional matrix of pixels of an image sensor organized into blocks of pixels forming macropixels, the sensor comprising a read circuit for reading each macropixel in one of a high resolution mode and a low resolution mode, wherein a single unique value is generated for all of the pixels of a macropixel in the low resolution mode and an individual value is generated for each pixel in the macropixel in the high resolution mode, the method comprising the steps of:
- determining which of the macropixels of the matrix are read in the high resolution mode and which of the macropixels of the matrix are read in the low resolution mode only, by:
- reading all of the macropixels of the matrix in the low resolution mode;
- detecting the macropixels of the matrix in which a movement is occurring based on values of the macropixels read in the low resolution mode;
- activating/maintaining the high resolution mode for the macropixels in which a movement is occurring;
- activating the high resolution mode for the macropixels in which no movement is occurring and which are located in a neighborhood of the macropixels in which the movement is occurring;
- activating/maintaining the low resolution mode only for the other micropixels of the matrix;
- and
- reading in high resolution mode the macropixels activated in the high resolution mode;
- storing, for each of the macropixels switching from the low resolution mode to the high resolution, individual pixel values for each pixel of the macropixel read in high resolution mode, thereby forming a reference macropixel for said macropixel;
- correcting each individual pixel value of the macropixel read in the high resolution mode by evaluating a difference between the individual pixel value and the corresponding individual pixel value of the reference macropixel;
- and
- at least one of storing and displaying the corrected pixel values of each of the macropixels read in the high resolution mode.
A device for detecting and tracking moving objects using a two-dimensional matrix of pixels of an image sensor organized into blocks of pixels forming macropixels, the device comprising:
- means for reading each macropixel in a high resolution mode and in a low resolution mode, wherein a single unique value is generated for all pixels of a macropixel in the low resolution mode and an individual value is generated for each pixel in the macropixel in the high resolution mode,
- means for determining which of the macropixels of the matrix are read in the high resolution mode and which of the macropixels of the matrix are read in the low resolution mode only, by:
- detecting the macropixels of the matrix in which a movement is occurring based on values of the macropixels read in the low resolution mode;
- activating/maintaining the high resolution mode for the macropixels in which a movement is occurring;
- activating the high resolution mode for the macropixels in which no movement is occurring and which are located in a neighborhood of the macropixels in which a movement is occurring;
- and
- activating/maintaining the low resolution mode only for the other macropixels of the matrix;
- means for correcting each individual pixel value of each macropixel read in the high resolution mode, comprising:
- means for storing individual pixel values of said macropixel read in the high resolution mode at the moment of switching from the low resolution mode to the high resolution mode for reading said macropixel, thereby forming a reference macropixel for said macropixel;
- and
- means for evaluating a difference between said individual pixel value and the corresponding value of the reference macropixel read in the high resolution mode;
- and
- means for at least one of storing and displaying the corrected pixel values of the macropixels read in the high resolution mode.
Dependencies are inferred from the claim text.