1. An image conversion apparatus for converting an input image signal representing input images into an output image signal representing output images, comprising: a filter, responsive to receiving the input image signal, having a kernel size of a first area of pixels for selecting a group of connected input pixels from an input image for luminance value increase, the group of connected input pixels (i) corresponding to a highlight of the input image having a brightness that is near a maximum of a dynamic range of the input image, (ii) having a size of limited dimensions which is relatively small relative to a size of the input image, and (iii) further having high luminance values relative to luminance values of neighboring pixels in a region of a second area of pixels, the second area of pixels being a little bigger than the first area of pixels; and a pixel processor, responsive to receiving the input image signal and an output of the filter, for assigning luminance values to output pixels of an output image on basis of the respective luminance values of the input pixels of the input image, wherein the pixel processor re-creates highlights of the input image as a visual appearance of sparkle by (i) selectively increasing luminance values of the selected group of connected input pixels corresponding to input image bright areas having limited dimensions which extend over less than a number of pixels in the kernel size of the filter and (ii) maintaining original luminance values of both (ii)(a) larger bright areas of the input image, except for the selected group of connected input pixels corresponding to input image bright areas having limited dimensions, and (ii)(b) dark areas of the input image to avoid a significant increase of average luminance of the output image over the input image.