A symmetric type image filter processing apparatus having a symmetric type
image filter composed of symmetric kernel coefficients, in which SIMD
commands are utilized efficiently for making the filtering processes high
speed, is provided. The symmetric type image filter processing apparatus
provides a row-wise intermediate data generating section, a row-wise
intermediate data utilizing section, and a memory. The row-wise
intermediate data generating section multiplies each kernel coefficient
of M pieces in each column of {(N+1)/2} columns at the right or left
column by each pixel of M pieces in the column direction of image data
having P pixels in one row, and cumulatively adds the multiplied results,
by using SIMD commands that can process sequential data of Q pieces. This
multiplication and addition operation is executed P/Q times, and
intermediate data in one row of the image data are generated and stored
in an intermediate data storing region in the memory. The row-wise
intermediate data utilizing section reads out the intermediate data
storing in the intermediate data storing region of the memory. And
operation result pixels are calculated by cumulatively adding the
intermediate data.