METHOD AND DEVICE FOR TESTING CRUSHING OF GLASS PLATE IMAGE PICKUP METHOD FOR GLASS TEST, AND IMAGE SIGNAL PROCESSING METHOD USED THE METHOD

PROBLEM TO BE SOLVED: To perform a highly precise crushing test with good workability capable of automatically processing the counting of the number of crushed pieces by directly electronically taking the projected image of a crushed sample glass followed by image processing. SOLUTION: This crushing test device has an image pickup part 1 for taking the image of a crushed sample glass 3, and an image processing part 2 for inputting the image data of the sample glass 3 obtained in the image pickup part 1 and performing operations such as counting of the number of crushed pieces and calculation of the area of the maximum crushed piece and the length of the longest crushed piece. In a crushing test, the sample glass 3 is crushed with a sheet-like screen member being arranged closely to one surface of the sample glass 3. A light is irradiated from the other surface side of the sample glass 3 to electronically directly take the projected image of the crushed sample glass 3 by a camera 5 from the arrangement surface side of the screen member. In the image processing part 2, counting of the number of crushed pieces of the crushed sample glass 3 is performed by means of an automatic processing such as binarizing processing on the basis of the resulting density image signal.