A printer driver of a Non-PC controls to quantize image data at quantization resolution (resolution 1), convert the quantized data into data resolution (resolution 2), and then transfer the data of the data resolution to an engine unit of an image output apparatus. The engine unit converts the data resolution of the received data into recording resolution (resolution 3) for a recording medium. Here, the quantization resolution is set to be lower than the data resolution. Thus, processing loads in the image processing unit can be reduced, whereby it is possible to provide image output capable of maintaining image quality and speed even under the circumstance that there is no sufficient memory and high-speed CPU, and to provide image output capable of maintaining image quality and speed according to a matrix recording method flexibly coping with various environments and minimizing the load in the engine unit.