Abstract: An image lens distortion correcting method having step (A) for printing an arbitrary image I1 in a computer; step (B) for photographing the printed image I1 with a camera having a lens distortion and obtaining a photographed image I2 in the computer; step (C) for obtaining a parameter &thgr; such that the image I1 is artificially distorted with the parameter &thgr; and an obtained distorted image I1ud equals with the photographed image 2; and step (D) for using the obtained parameter &thgr; to correct the image photographed by the camera. Thereby, (1) no correspondence point needs to be given, (2) no special tool or object is used, and (3) all points on the image are used, so that an internal parameter can automatically be obtained with high precision, and image lens distortion can be corrected with high precision.

Abstract: There is disclosed an image lens distortion correcting method comprising: an image printing step (A) for printing an arbitrary image I1 in a computer; an image pickup step (B) for photographing the printed image I1 with a camera having a lens distortion and obtaining a photographed image I2 in the computer; a parameter estimating step (C) for obtaining a parameter &thgr; such that the image I1 is artificially distorted with the parameter &thgr; and an obtained distorted image I1ud equals with the photographed image I2; and an image correcting step (D) for using the obtained parameter &thgr; to correct the image photographed by the camera. Thereby, (1) no correspondence point needs to be given, (2) any special tool or object is not used, and (3) all points on the image are used, so that an internal parameter can automatically be obtained with high precision, and an image lens distortion can be corrected with high precision.

Abstract: In order to provide a method for estimating a heart rate variability and the apparatus for embodying such estimation which can be operated at a low sampling frequency without detecting peaks on a waveform in electrocardiogram data, a method for estimating a heart rate variability from electrocardiogram data is arranged in such that frequencies in each of which a spectrum is maximum at a predetermined time are detected from the electrocardiogram data, and a heart rate variability is estimated on the basis of results obtained by filtering the electrocardiogram data with a band pass filter including the frequency detected as its center frequency.

Abstract: A person to be tested steps on a pair of foot steps, and a plurality of body load detectors sense the body load of the person, as applied to the foot steps. An arithmetic circuit receives the body load signals and provides difference signals which are displayed so that the person being tested can observe them. The person being tested sees body load distribution patterns on the display, and adjusts his body balance as a function thereof. Maximum-length linear shift register signals are provided which unbalance the body load distribution of the person being tested while standing on the foot steps. When the person observes these signals in the form of target signals, that person attempts to adjust the body load distribution so as to result in a balanced condition.