A method and a system for digital direct imaging, an image generating method and an electronic device are provided. The method for digital direct imaging includes: obtaining a first image of a first format; converting the first image into a second image of a second format, wherein the second image includes a contour description; generating a correction parameter according to at least one mark on a substrate; correcting the second image according to the contour description and the correction parameter; and performing a rasterization operation on the corrected second image and imaging the second image processed by the rasterization operation on the substrate by an exposure device.

In an example method, a set of source pixels corresponding to an image to be printed and a dot pattern of pixels including information to be encoded across the image are received. The dot pattern of pixels is mapped to a corresponding subset of the source pixels. A value of a clipping channel color in the subset of the source pixels is modified based on an original value of the clipping channel color for each pixel in the subset. The clipping channel color is used to detect the dot pattern of pixels. The image including the subset of pixels with modified clipping channel colors is printed.

The present document provides image processing methods and apparatus. One claim recites: obtaining a signal to be encoded in color image data, the signal comprising a plural-bit payload; predicting a resulting color of overprinting several inks on a substrate, the overprinting representing the color image data encoded with the signal; using the resulting color for both i) visibility evaluation of the overprinting, and ii) signal robustness evaluation of the overprinting as seen by an imaging device. Other claims and combinations are provided.

A graphical indicator comprising a plurality of first header blocks, a plurality of second header blocks and a plurality of data blocks for forming an indicator matrix is provided. Each of the first and second header blocks has a header graphical micro-unit, and each of the data blocks has a data graphical micro-unit. An array area is formed by the second header blocks and the data blocks. A first virtual line and a second virtual line are respectively formed by virtual centers of the first and second header blocks, and an included angle between the first and second virtual lines is less than 90 degrees.

In an example method, a dot pattern of pixels including information to be encoded across an image is mapped to a corresponding subset of the grayscale source pixels corresponding to the image to be printed. A value of a grayscale pixel in the subset of the grayscale source pixels is modified based on based on a predetermined threshold pixel value. The value of the grayscale pixel is decreased in response to detecting that the predetermined threshold pixel value is exceeded. The clipping channel color is used to detect the dot pattern of pixels. The image including the subset of pixels with modified values is printed.

A watermark image may be generated that includes a first set of encoded pixels each of which is assigned a first transparency value and a second set of encoded pixels each of which is assigned a second transparency value, the second transparency level being different from the first transparency level. The encoded pixels may be distributed among a set of blank pixels such that each encoded pixel neighbors one or more blank pixels in the watermark image, and in particular at least two blank pixels in the watermark image. Herein, each blank pixel may be assigned the second transparency value. The watermark image may be overlaid and blended over a background source image to create an encoded source image. A decoder system may recover encoded information from the encoded source image.

A graphical indicator comprising a plurality of first header blocks, a plurality of second header blocks and a plurality of data blocks for forming an indicator matrix is provided. Each of the first and second header blocks has a header graphical micro-unit, and each of the data blocks has a data graphical micro-unit. An array area is formed by the second header blocks and the data blocks. A first virtual line and a second virtual line are respectively formed by virtual centers of the first and second header blocks, and an included angle between the first and second virtual lines is less than 90 degrees.

The present disclosure relates generally to encoding signals for spot colors. In one implementation a substitute spot color+CMY tint is selected to replace an original spot color. The CMY tint can be transformed to carry an encoded signal. Of course, other features, combinations and technology are described herein.

In an example method, a dot pattern of pixels including information to be encoded across an image is mapped to a corresponding subset of the grayscale source pixels corresponding to the image to be printed. A value of a grayscale pixel in the subset of the grayscale source pixels is modified based on based on a predetermined threshold pixel value. The value of the grayscale pixel is decreased in response to detecting that the predetermined threshold pixel value is exceeded. The clipping channel color is used to detect the dot pattern of pixels. The image including the subset of pixels with modified values is printed.

A watermark image may be generated that includes a first set of encoded pixels each of which is assigned a first transparency value and a second set of encoded pixels each of which is assigned a second transparency value, the second transparency level being different from the first transparency level. The encoded pixels may be distributed among a set of blank pixels such that each encoded pixel neighbors one or more blank pixels in the watermark image, and in particular at least two blank pixels in the watermark image. Herein, each blank pixel may be assigned the second transparency value. The watermark image may be overlaid and blended over a background source image to create an encoded source image. A decoder system may recover encoded information from the encoded source image.