Disclosed is an optical fiber coating device for coating the outer circumference of the optical fiber with the coating material, in which the coating device is provided with and a gas provider for providing an environmental gas within the coating device, and a cooler for cooling down the environmental gas provided to the coater from the gas provider. Predictive lossless coding can operate on a macroblock basis for compatibility with existing image and video codecs. Of these candidates, a motion vector detector obtains a candidate with a small evaluation value based on prediction errors and motion vector cost as a motion vector, thereby generating an interpolation frame Ft-0.