Enhancing image data

摘要

The invention concerns image processing that includes the estimation of the optical depths of points in image data in order to enhance the image data. In particular but not limited to, from the optical depth noise present in the image due to aerosol in the scene, such as fog or haze, can be reduced. The invention concerns determining a first cost for each point independently based on a determined metric (60) and then a second cost based on an expected correlation in neighboring points (70). The two costs are then optimized (80) to determine an estimated optical depth for each point (80) that is then used to reduce the effect of aerosol in the image (84). Applications of the invention include, but is not limited to, surveillance systems so that objects in the scene of the image can be better identified once the image data has been enhanced to reduce the estimated noise. Aspects of the invention include a method, software, computer apparatus and a field programmable gate array.

主权项

1. A method of enhancing image data representing an image of a scene including aerosols, the method comprising:
(a) associating a first cost to each point in the image data based on a determined metric of that point having a candidate optical depth, where the determined metric of that point is independent of the determined metric of remaining points in the image; (b) associating second costs to sets of two or more points in the image, where each second cost is based on the candidate optical depths of the points of the associated set compared to at least one predetermined correlation of optical depths of points in a set; (c) determining an estimate optical depth for each point by optimising a combination of the first costs and second costs; and (d) for each point, using the respective estimated optical depth to enhance that point in the image data.