HARDENED CONCRETE BUBBLE MEASURING METHOD AND BUBBLE MEASURING INSTRUMENT

摘要

A hardened concrete bubble measuring method and instrument in which all problems of long extraction time to extract bubble parts, troublesome extraction work, intricate extraction device and arrangement, insufficient reliability of extraction results, and the like are solved. A bubble contained in hardened concrete is measured by performing feature amount extraction of an image at the opening part of a hole surrounding a bubble appearing in a measuring region using a first bubble image obtained through image processing of a density difference image between a first image captured by a digital camera under illumination from a first illumination means projecting illumination light at a large angle to the measuring region on the surface to be measured of a test piece of hardened concrete and a second image captured by a second illumination means projecting illumination light at a small angle to the measuring region, and a second bubble image obtained through image processing of a third image of the measuring region captured under illumination from an illumination means for illuminating the measuring region with illuminance exceeding a specified level.