Abstract: When an nth frame of encoded data is stored in a compressed-data storage area that stores 15 frames of encoded data, a target amount of code of the nth frame is decided so as to become a value that is the result of dividing the residual capacity of an area remaining in the compressed-data storage area by the number of remaining images to be stored in this remaining area. This makes it possible to prevent the target amount of code from becoming very large or very small. Even if there is a change in a photographic scene, therefore, a drastic change in image quality from frame to frame can be prevented.

Abstract: A method and an apparatus for controlling the quantity of codes representative of image data are disclosed. Image data representative of a single scene are thinned and then subjected to orthogonal transform in order to generate transform coefficients. The transform coefficients are normalized in accordance with the initial value of a normalization factor and then coded by compression. The quantity of the resulting codes is compared with a first target value. A value of the normalization factor corresponding to the first target value is calculated on the basis of the result of the above comparison in accordance with a relation between the normalization factor and the quantity of codes. Subsequently, the entire image data representative of a single scene are subjected to orthogonal transform, and the resulting transform coefficients are normalized by the above value of the normalization factor. The transform coefficients normalized by this normalization are coded by compression.