Image Interpolation Based on Gradient
基于图像梯度信息的插值方法

Image interpolation is a basic problem of image processing,in order to get a more reasonable weight function,the paper studies the application of gradients in one-dimensional signal interpolation,and generalizes it to the interpolation of image,then obtains a method for image interpolation based on gradients.In linear interpolation model,the weighted function is only dependent on the distance of the pixels,but not on the gradient,which often leads to the blurring of the image.Since image is a piecewise continual function,the gray value of an unknown pixel is closer to the pixel with smaller gradient than the pixel with bigger gradient,so a decreased weighted function of gradient is constructed in this method to interpolate the unknown pixels.It also discusses the selection of the related parameter in the model,and obtains a reasonable parameter based on the distribution of the gradient.The algorithm is tested on two images,all results show that the new method has higher peak signal to noise ratio and better intensity of image than known methods,and that it suits to simple image especially.