Image mosaicking is one of the most important tasks in the generation of orthophoto maps

which includes geometric mosaicking and gray seam line removal Geometric mosaicking can be strictly realized in computer according to the theory of Photogrammetry

whereas gray seam line removal is almost not well resolved The focus of the paper lies on the removal of the gray seam lines in the mosaicked image Firstly

the analysis of the advantages and disadvantages of existing methods such as ″ wavelet transform method ″ and ″overlapping image method ″is performed

and then the hard correction method is presented and tested using many real images The main idea of this method is as follows:for every piexl of cut lines in the whole mosaicked image

if it is the left right one

we compute the average gray difference between the pixels within a certain extent of the two sides of the cut line

and then adjust the gray difference to the pixels at a certain extent of the two sides of the cut line;if it is the top bottom one

this operation is done in top bottom sides of the cut line The results indicate that the method proposed above is very effective

simple

easy to realize and fit for gray level and color images