Image processing apparatus and method

A process of smoothing an input signal, the input signal comprising a succession of frames, each frame comprising a succession of pixels, the process comprising, for each pixel of the input signal:

• i) smoothing the pixel using a time constant (CO) for such pixel, thereby generating a smoothed pixel value (LO);
• ii) determining whether there exists a significant variation between such pixel and the same pixel in a previous frame, including determining whether the absolute value of the difference (AB) between the given pixel value (PI) and the value of such pixel in a smoothed prior frame (LI) exceeds a threshold (SE);
• and
• iii) modifying the time constant (CO) for such pixel to be used in smoothing the pixel in subsequent frames of the input signal based upon the existence or non-existence of a significant variation;
• wherein smoothing the input signal comprises, for each pixel, (a) modifying a time constant (CO) for pixel such based upon the existence of a significant variation as determined in step ii), and (b) determining a smoothed value for the pixel (LO) as follows:
• LO = LI + PI - LI CO .

A process for identifying an area in relative movement in an input signal, the input signal comprising a succession of frames, each frame comprising a succession of pixels, the process comprising:

• generating a first array indicative of the existence of significant variation in the magnitude of each pixel between a current frame and a prior frame;
• generating a second array indicative of the magnitude of significant variation of each pixel between the current frame and a prior frame;
• establishing a first moving matrix centered on a pixel under consideration and comprising pixels spatially related to the pixel under consideration, the first moving matrix traversing the first array for consideration of each pixel of the current frame;
• and
• determining whether the pixel under consideration and each pixel of the pixels spatially related to the pixel under consideration along an oriented direction relative thereto within the first matrix are a particular value representing the presence of significant variation, and if so, establishing in a second matrix within the first matrix, centered on the pixel under consideration, and determining whether the amplitude of the pixels in the second matrix spatially related to the pixel under consideration along an oriented direction relative thereto are indicative of movement along such oriented direction, the amplitude of the variation along the oriented direction being indicative of the velocity of movement, the size of the second matrix being varied to identify the matrix size most indicative of movement.

An apparatus for identifying relative movement in an input signal, the input signal comprising a succession of frames, each frame comprising a succession of pixels, the apparatus comprising:

• means for smoothing the input signal using a time constant for each pixel, thereby generating a smoothed input signal;
• means for determining for each pixel in the smoothed input signal a binary value corresponding to the existence of a significant variation in the amplitude of the pixel signal between the current frame and the immediately previous smoothed input frame, and for determining the amplitude of the variation;
• means for using the existence of a significant variation for a given pixel to modify the time constant for the pixel to be used in smoothing subsequent frames of the input signal;
• means for forming a first matrix comprising the binary values of a subset of the pixels of the frame spatially related to each particular pixel, and for forming a second matrix comprising the amplitude of the variation of the subset of the pixels of the frame spatially related to such particular pixel;
• and
• means for determining in the first matrix a particular area in which the binary value for each pixel is a particular value representing significant variation, and, for such particular area, for determining in the second matrix whether the amplitude varies along an oriented direction relative to the particular pixel in a known manner indicating movement of the pixel in the oriented direction, the amplitude of the variation along the oriented direction determining the velocity of movement of the pixel.

An apparatus for smoothing an input signal, the input signal comprising a succession of frames, each frame comprising a succession of pixels, the apparatus comprising:

• means for smoothing each pixel of the input signal using a time constant (CO) for such pixel, thereby generating a smoothed pixel value (LO);
• and
• means for determining the existence of a significant variation for a given pixel, and modifying the time constant (CO) for the pixel to be used in smoothing the pixel in subsequent frames of the input signal based upon the existence of such significant variation,
• wherein the means for determining the existence of a significant variation for a given pixel comprises means for determining whether the absolute value of the difference (AB) between the given pixel value (PI) and the value of such pixel in a smoothed prior frame (LI) exceeds a threshold (SE);
• and
• wherein the means for smoothing the input signal comprises, for each pixel, i) means for modifying a time constant (CO) for such pixel based upon the existence of a significant variation, and ii) means for determining a smoothed value for the pixel (LO) as follows:
• LO = LI + PI - LI CO .

An apparatus for smoothing an input signal, the input signal comprising a succession of frames, each frame comprising a succession of pixels, the apparatus comprising:

• means for smoothing each pixel of the input signal using a time constant (CO) for such pixel, thereby generating a smoothed pixel value (LO);
• means for determining the existence of a significant variation for a given pixel, and modifying the time constant (CO) for the pixel to be used in smoothing the pixel in subsequent frames of the input signal based upon the existence of such significant variation;
• and
• means for generating an output signal comprising, for each pixel, a binary value (DP) indicating the existence or non-existence of a significant variation, and the value of the time constant (CO).

An apparatus for identifying an area in relative movement in an input signal, the input signal comprising a succession of frames, each frame comprising a succession of pixels, the apparatus comprising:

• means for generating a first array indicative of the existence of significant variation in the magnitude of each pixel between a current frame and a prior frame;
• means for generating a second array indicative of the magnitude of significant variation of each pixel between the current frame and a prior frame;
• means for establishing a first moving matrix centered on a pixel under consideration and comprising pixels spatially related to the pixel under consideration, the first moving matrix traversing the first array for consideration of each pixel of the current frame;
• and
• means for determining whether the pixel under consideration and each pixel along an oriented direction relative to the pixel under consideration within the first matrix is a particular value representing the presence of significant variation, and if so, for establishing a second matrix within the first matrix, centered on the pixel under consideration, and for determining whether the amplitude of the pixels in the second matrix are indicative of movement along an oriented direction relative to the pixel under consideration, the amplitude of the variation along the oriented direction being indicative of the velocity of movement, the size of the second matrix being varied to identify the matrix size most indicative of movement.

An apparatus for identifying the velocity of movement of an area of an input signal, the input signal comprising a succession of frames, each frame comprising a succession of pixels, the apparatus comprising:

• means for determining for each pixel in the input signal a binary value corresponding to the existence of a significant variation in the amplitude of the pixel signal between the current frame and the immediately previous frame, and for determining the amplitude of the variation;
• means for forming, for each particular pixel of the input signal, a first matrix comprising the binary values of a subset of the pixels spatially related to such particular pixel, and a second matrix comprising the amplitude of the variation of the subset of the pixels spatially related to such particular pixel;
• and
• means for determining in the first matrix whether for a particular pixel, and other pixels along an oriented direction relative to the particular pixel, the binary value for each pixel is a particular value representing significant variation, and, for such particular pixel and other pixels, determining in the second matrix whether the amplitude varies along an oriented direction relative to the particular pixel in a known manner indicating movement of the pixel and the other pixels, the amplitude of the variation along the oriented direction determining the velocity of movement of the pixel and the other pixels.