Abstract: This description relates to image feature extraction. In some examples, a system can include a keypoint detector and a feature list generator. The keypoint detector can be configured to upsample a keypoint score map to produce an upsampled keypoint score map. The keypoint score map can include feature scores indicative of a likelihood of at least one feature being present at keypoints in an image. The feature list generator can be configured to identify a subset of keypoints of the keypoints in the image using the feature scores of the up sampled keypoint score map, determine descriptors for the subset of keypoints based on a feature description map, and generate a keypoint descriptor map for the image based on the determined descriptors.

Abstract: A method for estimating time to collision (TTC) of a detected object in a computer vision system is provided that includes determining a three dimensional (3D) position of a camera in the computer vision system, determining a 3D position of the detected object based on a 2D position of the detected object in an image captured by the camera and an estimated ground plane corresponding to the image, computing a relative 3D position of the camera, a velocity of the relative 3D position, and an acceleration of the relative 3D position based on the 3D position of the camera and the 3D position of the detected object, wherein the relative 3D position of the camera is relative to the 3D position of the detected object, and computing the TTC of the detected object based on the relative 3D position, the velocity, and the acceleration.

Abstract: According to an aspect, a video encoder selects a block of intermediate size from a set of block sizes for intra-prediction estimation for encoding a video signal. A set of neighbouring blocks with the intermediate size are tested for combining. If the set of neighbouring blocks are determined to be combinable, the video encoder selects a larger block size formed by the tested neighbouring blocks for encoding. On the other hand, if the set of neighbouring blocks are determined to be not combinable, the video encoder selects a smaller block size from the set of tested neighbouring blocks for prediction. According to another aspect, the best mode for intra-prediction is determined by first intra-predicting a block with intermediate modes in a set of modes. Then the intra-predictions are performed for the neighbouring modes of at least one intermediate mode.

Abstract: Several methods and systems for estimating motion in a plurality of multimedia pictures are disclosed. In an embodiment, at least one temporal distance between a multimedia picture and one or more reference pictures corresponding to the multimedia picture in a capture order associated with the plurality of multimedia pictures is computed. The at least one temporal distance is computed subsequent to an encoding of the multimedia picture. At least one motion estimation parameter is determined based on the at least one temporal distance. Motion associated with a subsequent multimedia picture to be encoded is estimated based on the at least one motion estimation parameter.

Abstract: A video encoder receives a minimum number of bits (MIN) and a maximum number of bits (MAX) to be used to encode a segment of a sequence of image frames, the segment including a set of pictures contained in the sequence of image frames. The video encoder encodes the set of pictures using a total number of bits greater than the minimum number of bits (MIN), and not exceeding the maximum number of bits (MAX). Thus, the transmission bit-rate of the video encoder can be constrained to lie within a maximum and minimum rate. In an embodiment, the constraints are enforced over relatively short time intervals.

Abstract: This invention predicts that intra mode prediction is more effective for the macroblocks where motion estimation in inter mode prediction fails. This failure is indicated by a large value of the inter mode SAD. This invention performs intra mode prediction for only macro blocks have larger inter mode SADs. The definition of a large inter mode SAD differs for different content. This invention compares the inter mode SAD of a current macroblock with an adaptive threshold. This adaptive threshold depends on the average and variance of the SADs of the previous predicted frame. An adaptive threshold is calculated for each new predictive frame.

Abstract: Several methods and systems for estimating motion in a plurality of multimedia pictures are disclosed. In an embodiment, at least one temporal distance between a multimedia picture and one or more reference pictures corresponding to the multimedia picture in a capture order associated with the plurality of multimedia pictures is computed. The at least one temporal distance is computed subsequent to an encoding of the multimedia picture. At least one motion estimation parameter is determined based on the at least one temporal distance. Motion associated with a subsequent multimedia picture to be encoded is estimated based on the at least one motion estimation parameter.

Abstract: Techniques for resizing data including receiving input data values for resizing, placing a first number of data values from a first line of data values of the input data values in a first portion of a first vector, placing the first number of data values from a second line of data values of the input data values in a second portion of the first vector, receiving a first matrix of weights, wherein each weight of the first matrix of weights corresponds to an amount of weight to apply to a data value for a point on a first line of a set of resized data, multiplying the first vector and the first matrix of weights to determine data values for the first line of the set of resized data, and outputting the set of resized data.

Abstract: Several techniques aimed at reducing computational complexity when encoding uses bi-predictively encoded frames (B-frames) are implemented in a video encoder. In an embodiment, B-frames are not used as reference frames for encoding P-frames and other B-frames. Non-use of B-frames allows a de-blocking filter used in the video encoder to be switched off when reconstructing encoded B-frames, and use of a lower complexity filter for fractional-resolution motion search for B-frames. In another embodiment, cost functions used in motion estimation for B-frames are simplified to reduce computational complexity. In one more embodiment, fractional pixel refinement in motion search for B-frames is simplified. In yet another embodiment, predictors used in motion estimation for a macro-block in a P-frame are selected from a B-frame that uses a same reference frame as the P-frame.

Abstract: A video encoder receives a minimum number of bits (MIN) and a maximum number of bits (MAX) to be used to encode a segment of a sequence of image frames, the segment including a set of pictures contained in the sequence of image frames. The video encoder encodes the set of pictures using a total number of bits greater than the minimum number of bits (MIN), and not exceeding the maximum number of bits (MAX). Thus, the transmission bit-rate of the video encoder can be constrained to lie within a maximum and minimum rate. In an embodiment, the constraints are enforced over relatively short time intervals.

Abstract: This invention predicts that intra mode prediction is more effective for the macroblocks where motion estimation in inter mode prediction fails. This failure is indicated by a large value of the inter mode SAD. This invention performs intra mode prediction for only macro blocks have larger inter mode SADs. The definition of a large inter mode SAD differs for different content. This invention compares the inter mode SAD of a current macroblock with an adaptive threshold. This adaptive threshold depends on the average and variance of the SADs of the previous predicted frame. An adaptive threshold is calculated for each new predictive frame.

Abstract: A method of rate control in coding of a video sequence to generate a compressed bit stream is provided that includes computing a sequence base quantization step size for a sequence of pictures in the video sequence, computing a picture base quantization step size for a picture in the sequence of pictures based on the sequence base quantization step size, a type of the picture, and a level of the picture in a rate control hierarchy, and coding the picture using the picture base quantization step size to generate a portion of the compressed bit stream.

Abstract: Advanced driver assistance systems can be designed to recognize and to classify traffic signs under real time constraints, and under a wide variety of visual conditions. This disclosure provides techniques that employ binary masks extracted by color space segmentation, with a different binary mask generated for each sign shape. Temporal tracking is employed to add robustness to the detection system. The system is generic, and is trainable to the traffic signs used in various countries.

Abstract: Several techniques aimed at reducing computational complexity when encoding uses bi-predictively encoded frames (B-frames) are implemented in a video encoder. In an embodiment, B-frames are not used as reference frames for encoding P-frames and other B-frames. Non-use of B-frames allows a de-blocking filter used in the video encoder to be switched off when reconstructing encoded B-frames, and use of a lower complexity filter for fractional-resolution motion search for B-frames. In another embodiment, cost functions used in motion estimation for B-frames are simplified to reduce computational complexity. In one more embodiment, fractional pixel refinement in motion search for B-frames is simplified. In yet another embodiment, predictors used in motion estimation for a macro-block in a P-frame are selected from a B-frame that uses a same reference frame as the P-frame.

Abstract: Techniques including receiving a distorted image from a camera disposed about a vehicle, detecting, in the distorted image, corner points associated with a target object, mapping the corner points to a distortion corrected domain based on one or more camera parameters, mapping the corner points and lines between the corner points back to a distorted domain based on the camera parameters, interpolating one or more intermediate points to generate lines between the corner points in the distortion corrected domain mapping the corner points and the lines between the corner points back to a distorted domain based on the camera parameters, and adjusting a direction of travel of the vehicle based on the located target object.

Abstract: This description relates to image feature extraction. In some examples, a system can include a keypoint detector and a feature list generator. The keypoint detector can be configured to upsample a keypoint score map to produce an upsampled keypoint score map. The keypoint score map can include feature scores indicative of a likelihood of at least one feature being present at keypoints in an image. The feature list generator can be configured to identify a subset of keypoints of the keypoints in the image using the feature scores of the up sampled keypoint score map, determine descriptors for the subset of keypoints based on a feature description map, and generate a keypoint descriptor map for the image based on the determined descriptors.

Abstract: Various embodiments of the present technology relate to using neural networks to detect objects in images. More specifically, some embodiments relate to the reduction of computational analysis regarding object detection via neural networks. In an embodiment, a method of performing object detection is provided. The method comprises determining, via a convolution neural network, at least a classification of an image, wherein the classification corresponds to an object in the image and comprises location vectors corresponding to pixels of the image. The method also comprises, for at least a location vector of the location vectors, obtaining a confidence level, wherein the confidence level represents a probability of the object being present at the location vector, and calculating an upper-bound score based at least on the confidence level.

Abstract: Techniques including receiving a distorted image from a camera disposed about a vehicle, detecting, in the distorted image, corner points associated with a target object, mapping the corner points to a distortion corrected domain based on one or more camera parameters, mapping the corner points and lines between the corner points back to a distorted domain based on the camera parameters, interpolating one or more intermediate points to generate lines between the corner points in the distortion corrected domain mapping the corner points and the lines between the corner points back to a distorted domain based on the camera parameters, and adjusting a direction of travel of the vehicle based on the located target object.

Abstract: A method and system for bit rate control during encoding of multimedia data are disclosed. A change in complexity of a multimedia picture relative to complexity associated with one or more multimedia pictures in a multimedia sequence is determined. A complexity associated with a multimedia picture is determined based on number of bits and an average quantization associated with the multimedia picture. A bit rate is adjusted for encoding the multimedia picture based on the change in complexity of the multimedia picture. The bit rate is increased on determining an increase in complexity of the multimedia picture and is decreased on determining a decrease in complexity of the multimedia picture. Utilization of additional bits during the increase in the bit rate and saving of bits during the decrease in the bit rate are compensated during adjusting of bit rates for encoding subsequent multimedia pictures in the multimedia sequence.

Abstract: A method of rate control in coding of a video sequence to generate a compressed bit stream is provided that includes computing a sequence base quantization step size for a sequence of pictures in the video sequence, computing a picture base quantization step size for a picture in the sequence of pictures based on the sequence base quantization step size, a type of the picture, and a level of the picture in a rate control hierarchy, and coding the picture using the picture base quantization step size to generate a portion of the compressed bit stream.