1. An image processing apparatus for removing haze from an image, the apparatus comprising: a haze brightness measurer configured to measure haze brightness in the image; a transmission estimator configured to estimate a blockwise transmission based on a final cost function value calculated by a contrast and an image loss of the image, and estimate a pixelwise transmission by using the blockwise transmission; and an image reconstructor configured to generate a reconstructed image by using the haze brightness and the pixelwise transmission.