A method and system to convert an electronic image file described in a page description language containing both contone and non-contone image objects to an intermediate binary format image. The intermediate format image separately encodes the contone and non-contone image objects. The contone image objects are edge-tagged. Prior to printing, the intermediate binary format page image is separated into the contone and non-contone image objects. The contone image objects are converted back to a contone form using the edge tagging to modify the filter weights of a digital filter. The non-contone image objects are converted to contone form by means of a pattern matching scheme.
A method of performing tonal transform on image data. The method includes extracting a portion of the image data, assigning one of a plurality of labels to the extracted portion, performing a first tonal transformation on the extracted portion if a first label is assigned to the extracted portion, and performing a second tonal transformation on the extracted portion if a second label is assigned to the extracted portion. The method can be performed, for example, with an image processor comprising a memory that stores the image data and a processor coupled to the memory.
A method and system to convert an image described in a page description language to a contone image. The contone image is halftoned and encoded to generate image data including edge tag data and image data. A tagged state value of each pixel of image data within a predefined neighborhood of pixels is determined. The image data is filtered using a predetermined set of filter weighting values wherein each pixel of image data within the predefined neighborhood of pixels has an associated filter weighting value. A predetermined filtered image value is assigned to each pixel having a tagged state indicating an edge pixel. A summation of all filtered image values for the predefined neighborhood of pixels is assigned when the tagged state of the pixel is a non-edge pixel.
