In the field of direct part marking technology

2D barcode is more and more widely used

but there is a problem that 2D barcodes marked on a cylindrical part have spatial distortions which will result in reading difficulties. Existing algorithms mostly attempt to recognize 2D barcode marked on the plane which only have perspective and incline distortion. However

they can hardly recognize 2D barcode marked on cylindrical part because the pattern of 2D barcode is changed by spatial distortion. For correcting this difficulty

a new method should be proposed to recovery the distorted 2D barcode

and the radius parameter of cylindrical part should be automatically got without manual measurement.We firstly analyze the principle of forming distorted 2D barcode marked on cylindrical parts

and we establish a spatially distorted 2D barcode correction model based on calibrated machine vision mechanism and the principle of perspective projection. then deduces the relationship between fitted ellipse and the radius of cylindrical part in the image

in addition

estimates the radius by the ellipse parameters. finally substitutes it into the correction model to get the corrected 2D barcode.In the experiment

we select two distorted 2D barcodes marked on the cylindrical parts with different radius parameter

and acquires pictures of them from different views. It gets fixed parameters of the machine vision device

based on that the spatially distorted 2D barcode correction model could be established.The experiment results show that

the two distorted 2D barcodes are recovered well and the processing time is limited in 1 second.Compared with previous methods

this algorithm is more concise because of prior calibration and spatial distortion mode. Besides

this algorithm is more automated because the radius parameter could be automatically got by the image.Based on camera calibration

the method is effective for correcting spatially distorted 2D barcode marked on arbitrary radius cylinder.The method extends the application range of 2D barcode that not only flat part but also cylindrical part could also be identified. However

in the future work it should introduce nonlinear distortion of the lens and get the more accurate camera calibration parameters for more ideal restoration result.