Halide is a programming language for image processing that aims to provide high-performance code across platforms. It separates the algorithm definition from the schedule to allow for architecture-specific optimization. Evaluation shows Halide outperforms other tools like ImageMagick and MATLAB for RGB to grayscale and Gaussian blur operations on test images, with execution times within 1-10% of the other fastest tool, OpenCV 2. Halide requires more learning than other tools but allows for easier optimization through its separation of algorithm and schedule.