This paper presents a global alignment model based image mosaicing method for camera-captured document images

and it can be used to combine multiple overlapping document images into one large image It corrects the perspective distortion with the estimated vanishing points

and there exists only an affine transform between two adjacent images Then

it adjusts the distance of featurepoints to distribute them as evenly as possible in the overlapping regions Thirdly

it uses local alignment constraints of all the overlapping image pairs to construct global alignment model

thus

to eliminate the error accumulation In order to reduce alignment error of overlapping area

a binary weighted function is used to blend the overlapping region of image pairs This method is unique because it does not require the calibration of the internal/external camera parameters in advance and does not restricting the camera position

thus allowing greater flexibility than scanner-based or fixed-camera-based approaches. It can produce a high resolution and accurate full page mosaic from small image patches of a document