An image processing apparatus and an image fine-tuning method are provided. The image processing apparatus includes a high-pass filter, a block comparator, an image data reconstructor, and a calculator. The high-pass filter receives a first image to generate a filtered image. The block comparator receives an input image and the first image to generate a block comparison result. The image data reconstructor receives the filtered image and the block comparison result to generate image reconstruction data. The calculator receives the input image and the image reconstruction data to generate an output image.