1. A system for generating a direction confidence measure, comprising: a sensor device that captures blur images of a photographic target; and a depth estimator that calculates matching errors for said blur images, said depth estimator then generating said direction confidence measure by utilizing said matching errors and a dynamic optimization constant that is selected depending upon image characteristics of said blur images, said blur images including a first blur image and a second blur image, said first blur image being set at a different focus setting than said second blur image, said depth estimator performing a depth estimation procedure by performing iterations of a kernel convolution process in a focus direction that proceeds from said first blur image towards said second blur image.