A method for processing pixels in rasterized image data includes a combination of text and photographic content. Each pixel having a discrete color value, a surround value based on the number of neighboring pixels having the same color value is determined. A division in blocks of two by two pixels is made and a critical number is determined based on the number of surround values lower than a predetermined threshold. This critical number has one of five possible values. Based on this critical number, a discrimination is made between noisy blocks, and flat blocks. The color values of pixels within a noisy block are replaced by an average of the color values of the pixels within the noisy block. For image data rasterized with 600 pixels per inch, this method does not deteriorate the image quality of text nor photographic content. The image data are more apt for lossless compression.