Abstract: A method for preventing blurring of an image includes the steps of projecting an image onto a photosensor array comprising a plurality of photosensors, monitoring a value proportional to a number of photons received by each photosensor in the array; determining a second derivative of the monitored value for each photosensor at least once during exposure; comparing the second derivative to a threshold value that varies during exposure, and recording the monitored value and time at which the second derivative has exceeded the threshold.

Abstract: A digital camera has a sensor array which removes subject motion blur by monitoring the rate at which charge is collected by the individual sensors within the array during scene imaging. If the rate at which photons are striking the sensor varies, then the brightness of the image which the sensor is viewing must be changing. When a circuit built in to the sensor array detects that the image brightness is changing, the amount of charge collected is preserved and the time at which brightness change was detected is recorded. Each pixel corresponding to each sensor where exposure was stopped is adjusted to the proper exposure by linearly extrapolating the exposure the sensor did receive so that the pixel corresponding to the sensor has an intensity corresponding to the dynamic range of the entire image. The image sensing array will preferably be implemented as active-pixel sensor CMOS image sensors.

Abstract: A digital camera has a sensor array which removes subject motion blur by monitoring the rate at which charge is collected by the individual sensors within the array during scene imaging. If the rate at which photons are striking the sensor varies, then the brightness of the image which the sensor is viewing must be changing. When a circuit built in to the sensor array detects that the image brightness is changing, the amount of charge collected is preserved and the time at which brightness change wag detected is recorded. Each pixel corresponding to each sensor where exposure was stopped is adjusted to the proper exposure by linearly extrapolating the exposure the sensor did receive so that the pixel corresponding to the sensor has an intensity corresponding to the dynamic range of the entire image. The image sensing array will preferably be implemented as active-pixel sensor CMOS image sensors.

Abstract: A technique for post-processing decoded compressed images to reduce decoding-related artifacts employs a maximum likelihood estimation of an original image f. The decoded image is modeled as a montage of “flat surfaces” of different intensities, where the number of flat surfaces and their intensities are generally different in different regions of the decoded image. The intensity of each pixel is conditionally adjusted to that of a corresponding flat surface in a window region surrounding the pixel. In a general algorithm, the flat surface model is fitted to the observed image by estimating the model parameters using the “k-means” algorithm and a hierarchical clustering algorithm. A cluster similarity measure (CSM) is used to determine the number of intensity clusters, and hence flat surfaces, in the model of a window region surrounding a pixel of interest. The pixel intensity is adjusted to an estimated value which is the mean intensity of the cluster in which the pixel falls.