Patent ID: 8593522
Filing Date: 2013-11-26
Classification: G02B,G03B,G06K,H04N

Abstract:
1. A digital camera which tracks images of a target on pictures successively captured, and executes, using a result of the tracking, at least one of an auto-focus process, an automatic exposure process, a framing process by camera control, and an automatic shooting process by camera control, the digital camera comprising: a storage that stores a first transform parameter and information about an initial region, the initial region being a region on a first picture and including an image of the target, and the first transform parameter being a parameter that (i) corresponds to an image-capture environment in which the first picture is captured and (ii) transforms the first picture into a picture having a predetermined image quality; a transform parameter calculator that calculates a second transform parameter according to an image-capture environment in which a second picture captured after the first picture is captured, the second transform parameter being a parameter for transforming the second picture into a picture having the predetermined image quality; a first picture transformer that transforms the first picture into a picture for search having an image quality corresponding to an image quality of the second picture, using the first transform parameter stored in the storage and the second transform parameter calculated by the transform parameter calculator; a tracking processor that tracks the images of the target by searching the second picture, for a target region having an amount of characteristics that is close to an amount of characteristics that quantitatively indicates characteristics of a region which is in the picture for search and corresponds to the initial region; a second picture transformer that transforms the second picture into a picture for output, using a third transform parameter different from the second transform parameter; and an output that outputs the picture and information indicating a position of the target region searched for by the tracking processor, wherein a variation between a picture immediately previous to the second picture and the picture for output is less than a variation between the immediately previous picture and a picture obtained as a result of transforming the second picture using the second transform parameter, and wherein the transform parameter calculator: calculates the second transform parameter as the third transform parameter when a difference value between the second transform parameter and an old third transform parameter is smaller than or equal to a predetermined threshold, the old third transform parameter being used to calculate an image for output which is immediately previous to the image for output in a sequence of successively captured pictures; and calculates, as the third transform parameter, a value which makes the difference value between the second transform parameter and the old third transform parameter equal to the predetermined threshold when the difference value between the second transform parameter and the old third transform parameter is greater than the predetermined threshold.