Thousand to one: An image compression system via cloud search
With the advent of the `big data' era, a huge number of images are produced every day. Traditional image compression methods no longer satisfy the demand to store and transmit them. In this paper, we face this challenge and take advantage of the correlations existing between images to achieve a higher compression rate. We propose an image compression system that encodes each image by referencing its correlated images in the cloud. We first extract features from an image and retrieve its similar image from the massive images in the cloud by comparing these features. Then we preprocess the retrieved picture by applying projective transformation and illumination compensation to obtain multiple reference images of higher prediction accuracy. By taking advantage of the redundancy between the reference images and the current image, we encode the current image through prediction coding techniques. The experimental results demonstrate that the proposed method outperforms JPEG and HEVC intra coding by 61.5% and 21.3% on average, respectively. It has an average compression ratio of over a thousand to one.