Abstract: A strain measuring device is provided which is not affected by a change in the intensity and irradiation direction of light received by a measurement target and which enables stable measurement. A computer functions as minute region extracting device for extracting respective surface height distributions of minute regions a and b containing points A and B in a predetermined region from an initial surface height distribution obtained by measuring the predetermined region (6) of the measurement target by a surface height measuring device, coordinate calculating device for calculating coordinates of points A? and B? in minute regions a? and b? most similar to the minute regions a and b over a time-advanced surface height distribution of the predetermined region 6 and corresponding to the points A and B in the minute regions a and b, respectively, and strain calculating device for calculating a strain in a direction of a line AB of the measurement target.

Abstract: Provided are a displacement/distortion measuring method and a displacement/distortion measuring apparatus for easily and highly accurately measuring displacement or distortion of an object. An image of the surface of the measuring object is picked up by a line scanner apparatus adhered or brought close to the surface of the measuring object. The image is taken, displacement or distortion is measured by image analysis of the image of the measuring object surface prior to time lapse and that after time lapse, and displacement or distortion measuring results are outputted.

Abstract: Provided are a displacement/distortion measuring method and a displacement/distortion measuring apparatus for easily and highly accurately measuring displacement or distortion of an object. An image of the surface of the measuring object is picked up by a line scanner apparatus adhered or brought close to the surface of the measuring object. The image is taken, displacement or distortion is measured by image analysis of the image of the measuring object surface prior to time lapse and that after time lapse, and displacement or distortion measuring results are outputted.