Security printing using mixed spot sizes in stochastic or frequency modulated halftone images
Methods and systems for securely rendering a security feature with image data to be printed, can involve providing within the image data, data relating to a group of spots, and within the image data, mixing spots of two or more spot sizes among the group of spots to embed information within a stochastic or frequency modulation halftone image. In an embodiment, operations may be implemented for rendering a part of the image with a first spot among the group of spots and a remaining portion of the image with a second spot among the group of spots, wherein the second spot is smaller in size than the first spot.
1. A method of securely rendering a security feature with image data to be printed, comprising:
providing within the image data, data relating to a plurality of spots;
within the image data, mixing spots of at least two spot sizes among the plurality of spots based on a level of drop size mixing with respect to the at least two spot sizes to embed information as a security feature within an image comprising at least one of a stochastic halftone image or a frequency modulated (FM) halftone image; and
rendering the image with a printer.
2. The method of claim 1 wherein rendering the image further comprises: rendering a part of the image with a first spot among the plurality of spots and a remaining portion of the image with a second spot among the plurality of spots, wherein the second spot is smaller in size than the first spot.
3. The method of claim 1 wherein rendering the image further comprises:
rendering the image using two states including a first state and a second state, wherein the first state among the two states utilizes larger sized spots as compared to the second state during a halftone rendering of the image; and
controlling a contrast of the rendering of the image according to differences in a mixing ratio of larger spots with respect to smaller spots among the plurality of spots.
4. The method of claim 1 further comprising:
controlling by a contone image, a continuous modulation of the mixing of the varying spot sizes among the plurality of spots to embed the information within the stochastic halftone image or the FM halftone image.
5. The method of claim 1 wherein the plurality of spots comprises more than two spots, wherein the more than two spots are used to create differentiations in the mixing.
6. The method of claim 1 further comprising:
detecting the embedded information by capturing an image of the embedded information; and
processing the image to reveal a hidden security mark in the embedded information.
7. The method of claim 1 further comprising:
capturing video containing the embedded image;
decoding the video of the embedded image; and
displaying on a display screen a decoded image containing the embedded image.
8. A system for securely rendering a security feature with image data to be printed, comprising:
at least one processor and a memory, the memory storing instructions to cause the at least one processor to perform:
providing within the image data, data relating to a plurality of spots;
within the image data, mixing spots of at least two spot sizes among the plurality of spots based on a level of drop size mixing with respect to the at least two spot sizes to embed information as a security feature within an image comprising at least one of a stochastic halftone image or a frequency modulated (FM) halftone image; and
rendering the image with a printer.
9. The system of claim 8 wherein the instructions for rendering the image are further configured for rendering a part of the image with a first spot among the plurality of spots and a remaining portion of the image with a second spot among the plurality of spots, wherein the second spot is smaller in size than the first spot.
10. The system of claim 8 wherein the instructions are further configured for:
rendering the image with the printer using two states including a first state and a second state, wherein the first state among the two states utilizes larger sized spots as compared to the second state during a halftone rendering of the image; and
controlling a contrast of the rendering of the image according to differences in a mixing ratio of larger spots with respect to smaller spots among the plurality of spots.
11. The system of claim 8 wherein the instructions are further configured for:
controlling by a contone image, a continuous modulation of the mixing of the varying spot sizes among the plurality of spots to embed the information within the stochastic halftone image or the FM halftone image.
12. The system of claim 8 the plurality of spots comprises more than two spots, wherein the more than two spots are used to create differentiations in the mixing.
13. The system of claim 8 wherein the instructions are further configured for:
detecting the embedded information by capturing an image of the embedded information; and
processing the image to reveal a hidden security mark in the embedded information.
14. The system of claim 8 wherein the instructions are further configured for:
capturing video containing video of the embedded image;
decoding the video of the embedded image in real time; and
displaying on a display screen, a decoded image containing the embedded image on a display screen.