| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic focus controller by which high-speed and highly accurate focusing operation is attained. SOLUTION: A digital still camera, shown in figure 1, is provided with a DSP core 44 to perform the DCT conversion of a picture data obtained, by performing image pickup at a focus lens position and a CPU 6 with which the average value of DCT coefficients obtained by the DCT conversion is calculated for each wave number and is arrayed in the ascending order of the wave number, and the wave number having a local minimum value is retrieved from the average value train of the DCT coefficients, arrayed in the ascending order of the wave number and a focal position is decided, by having the retrieved wave number as a focus index value. |
