Interpolation of one- and two-dimensional images with pixelwise photon number conservation

The interpolation of one- and two-dimensional images is considered. The usu al linear or cubic spline interpolations try to connect given data points. On the other hand, image data give area integrals of the radiation intensit y (i.e,, photon counts) over pixels. Based on variational principles? we ha ve developed schemes of quadratic and fourth-order polynomial interpolation which reproduce the given pixelwise photon counts exactly. These methods w ere tested on some simple examples and showed satisfactory results.