A method, image processing system, and computer-readable recording medium for item defect inspection are provided. The method is as follows. A test image and a reference image of a test item are received. A test block and a corresponding reference block are obtained from the test image and the reference image to generate a test block image and a reference block image. The test block image and the reference block image are respectively partitioned into multiple sub-blocks. All interfering sub-blocks are identified and filtered out from the test block image and the reference block image, and a shift calibration parameter is obtained accordingly. The test block in the test image is calibrated based on the shift calibration parameter to generate a calibrated test block image. The calibrated test block image and the reference block image are compared to obtain defect information of the test item corresponding to the test block.