Method and apparatus for processing image data

An image data processing apparatus for executing filtering bidimensional image data, comprising:

• a memory for storing said bidimensional image data having gradation data of each of pixels arranged in first and second directions, said pixels making up a bidimensional image;
• subject detection size setting means for setting a subject detection size defined by a preselected number of pixels in each of the first and second directions;
• connection area setting means for setting a connection area equal in size to said subject detection size in the first direction, and greater in size than said subject detection size in the second direction;
• data connecting means for sequentially obtaining the gradation data, pixel by pixel, in the second direction in said connection area to produce a gradation data sequence;
• FFT means for executing FFT to transform said gradation data sequence into frequency domain;
• separating means for separating data of preselected harmonics bins from an output from said FFT means, said preselected harmonics bins being determined in accordance with said subject detection size;
• and
• IFFT means for executing IFFT to transform data of said preselected harmonics bins from said separating means into time domain.

An image data processing apparatus to perform processing with respect to data of a bidimensional image, said bidimensional image including pixels arranged in horizontal and vertical directions, comprising:

• a horizontal direction filtering unit;
• a target size setting unit for setting a desired target size to be detected, said desired target size being defined by pixel numbers in said horizontal and vertical directions;
• a vertical direction filtering unit;
• and
• a superposing unit for superposing filtering results of said horizontal direction filtering unit and said vertical direction filtering unit to thereby output a final result of processing, wherein
• (A) said horizontal direction filtering unit includes:
• first setting means for setting a first connecting area in said bidimensional image in accordance with said desired target size;
• and
• first shifting means for sequentially shifting said first connecting area in the horizontal direction in said dimensional image to suppress image components less than a horizontal size of said desired target size, said first shifting means comprising means for sequentially obtaining pixel level data in said first connecting area in the vertical direction to produce first gradation data sequence, first FFT means for executing FFT to transform said first gradation data sequence into a frequency domain, and first separating means for separating first preselected frequency components from an output of said first FFT, and
• (B) said vertical direction filtering unit includes:
• second setting means for setting a second connecting area in said bidimensional image in accordance with said desired target size;
• and
• second shifting means for sequentially shifting said second connecting area in the vertical direction in said bidimensional image to suppress image components less than a vertical size of said desired target size, said second shifting means comprising means for sequentially obtaining pixel level data in said second connecting area in the horizontal direction to produce second gradation data sequence, and second FFT means for executing FFT to transform said second gradation data sequence into a frequency domain and second separating means for separating second preselected frequency components from an output of said second FFT,
• said first and second preselected frequency components being determined in accordance with said desired target size.

An image data processing method for processing data of a bidimensional image to extract a target from said bidimensional image, said bidimensional image including pixels arranged in horizontal and vertical directions, said data being representative of gradation of each of said pixels comprising:

• (a) setting a size of said target to be extracted, said size being defined by pixel number in said horizontal and vertical directions;
• (b) sequentially connecting, in a bidimensional connecting area determined in accordance with said size, data of pixels in said vertical and horizontal directions to produce a gradation change signal;
• (c) executing frequency analysis with said gradation change signal to thereby generate frequency harmonics components representative of said gradation change signal in a frequency domain;
• (d) selecting predetermined components from said frequency harmonics components, said predetermined components corresponding to said size of said target.

An image data processing apparatus for processing data of a bidimensional image to detect an object, said bidimensional image having pixels arranged in horizontal and vertical directions, said data being representative of gradation of each of said pixels, comprising:

• a memory for storing data of a bidimensional image;
• size setting means for setting a size of said object, said size being defined by pixel numbers in the horizontal and vertical directions;
• means for sequentially reading the gradation of each pixel in said vertical and horizontal directions in a connecting bidimensional area designated in said bidimensional image to produce a gradation change signal, said connecting bidimensional area being determined in accordance with said size of said object;
• transforming means for transforming said gradation change signal into a frequency domain to deliver a plurality of frequency components;
• and
• selecting means for selecting desired frequency components from said plurality of frequency components transformed by said frequency analyzing means, said desired frequency components corresponding to said size of said object.