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US 12,348,693 B1Granted
Smoothing edges when embedding PDF artwork elements
AssigneeDigimarc Corporation
InventorsTrent J. Brundage, Brian Johnson
Life of this patent
Estimating the term…
Abstract
The present disclosure relates generally to signal encoding for elements within PDF files. One implementation smooths saw-toothed edges of rasterized elements meant for encoding. Other implementations are provided too.
Claims20
An image processing method to embed a PDF file with a signal, the PDF file comprising a plurality of elements including a vector element, said method comprising:
- converting the vector element into a raster element, the raster element comprising a plurality of pixels, the raster element comprising at least one saw-tooth edge;
- embedding the raster element with a signal, the signal comprising a plural-bit payload, said embedding yielding an embedded raster element;
- layering the vector element under the embedded raster element, said layer yielding layered elements, in which the at least one saw-tooth edge is obscured by a corresponding edge of the vector element;
- including the layered elements within the PDF file.
1 more element
An image processing method to embed a PDF file with a signal, the PDF file comprising a plurality of elements including a vector element, said method comprising:
- converting the vector element into a raster element, the raster element comprising a plurality of pixels, the raster element comprising at least one saw-tooth edge;
- eroding the at least one saw-tooth edge by M pixels, where M is a positive integer, said eroding yielding an eroded saw-tooth edge;
- dilating the eroded saw-tooth edge by N pixels, where N is a positive integer, said dilating yielding a dilated, eroded saw-tooth edge, wherein pixel values for the N pixels are randomly chosen from pixel values associated with the plurality of pixels;
- embedding the raster element with an auxiliary signal, said embedding yielding an embedded raster element;
- establishing a clipping path inside of the dilated, eroded saw-tooth edge, in which pixels outside of the clipping path are not to be displayed or printed in association with the embedded raster element, said establishing a clipping path yielding a clipped, embedded raster element;
- including the clipped, embedded raster element within the PDF file.
3 more elements
An apparatus comprising:
- memory storing a PDF file, the PDF file comprising a plurality of elements including a vector element, said method comprising:
- means for changing the vector element into a raster element, the raster element comprising a plurality of pixels, the raster element comprising at least one saw-tooth edge;
- means for transforming the raster element to include a signal, the signal comprising a plural-bit payload, said means for transforming yielding an embedded raster element;
- means for layering the vector element under the embedded raster element in a layer, the layer including layered elements, in which the at least one saw-tooth edge is obscured by a corresponding edge of the vector element;
- means for including the layered elements within the PDF file.
2 more elements
A method comprising:
- receiving a vector element from a PDF file;
- converting the vector element into a rasterized element having one or more edges;
- embedding an information signal within the rasterized element while maintaining a keep-away zone of N pixels near the one or more edges of the rasterized element, where N is a positive integer, wherein the keep-away zone does not include the information signal embedded therein;
- eroding M pixels bordering the one or more edges of the embedded rasterized element, wherein M is a positive integer;
- layering the original vector element underneath the eroded, embedded rasterized element, wherein the keep-away zone is larger than the eroded pixels;
- and
- outputting the layered elements for display or printing, wherein the original vector element provides crisp edges while maintaining the embedded information signal in interior regions of the rasterized element.
4 more elements
Dependencies are inferred from the claim text.