IMAGE ENCODER APPARATUS, CONTROL METHOD AND CONTROL PROGRAM FOR THE IMAGE ENCODER APPARATUS AND RECORDING MEDIUM

PROBLEM TO BE SOLVED: To encode a depth value without delays, using simple processings.SOLUTION: An image encoder includes a depth-value analysis unit 14 that acquires a depth value for each unit area in an original image; counts the number of occurrences of the acquired depth values in the original image; creates a depth value distribution that is the distribution of the number of occurrences for each depth value; divides, based on the shape of the created depth value distribution, the range from a minimum value to a maximum value of the depth values in the depth value distribution into a plurality of sections; and assigns, to the depth values included in the divisional sections, codes that are different on a section-by-section basis. A depth value conversion unit 15, that uses the codes which are assigned by the depth value analysis unit 14 encodes the depth values to encode the original image and outputs the encoded image and the number of codes used for obtaining the encoded image, in association with each other. In this way, the depth values can be encoded merely from a single original image, so that the depth values can be encoded without delays and by using a simple processing.