According to examples, an apparatus may include a processor that may access a window of pixels corresponding to print data. The print data may specify printing of a plurality of pixels based on an original document image and image-independent print data. The apparatus may identify a first pixel, from among the window of pixels, corresponding to the image-independent print data, determine a characteristic associated with the window of pixels, determine, based on the characteristic, that the image-independent print data is to specify printing of a second pixel from among the window of pixels. The apparatus may cause the image-independent print data to specify printing of the second pixel based on the determination that the image-independent print data is to specify printing of the second pixel.

A method for checking the authenticity of products, by checking an image (A) of a product. The proof of authenticity is not visible to the human eye and cannot be copied. This is characterized in that a code stored in a halftone image by manipulation of dots and/or a manipulated field bounded in the halftone image can be read by means of an optical device and compared with a retrievable value in at least one database. In at least one field (F1 to F5) a part of a serial number is determined which describes the structure of the serial number and a hash function used for transmitting the serial number to the database, and this is also characterized in that the serial number is subsequently assembled and encrypted with the corresponding hash function.

The present disclosure relates generally to data hiding for retail product packaging and other printed objects such as substrates. One embodiment embeds an information signal in a spot color for printing on various substrates. The spot color is screened, and overprinted with process color tint. The tint is modulated prior to overprinting with optimized signal tweaks. The optimization can include consideration of a detector spectral dependency (e.g., red and/or green illumination). Many other embodiments and combinations are described in the subject patent document.

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 method, non-transitory computer readable medium and apparatus for generating a multi-layer correlation mark via a monochrome printer are disclosed. For example, the method includes setting a first scalar value of a channel of the monochrome printer, setting a second scalar value of the channel of the monochrome printer, generating a first layer of the multi-layer correlation mark at the first scalar value of the channel, generating a second layer of the multi-layer correlation mark at the second scalar value of the channel and printing the multi-layer correlation mark comprising the first layer at the first scalar value of the channel and the second layer at the second scalar value of the channel.

An image processing apparatus includes: an embed-data generating unit configured to generate embed-data, which is to be embedded in input-image-data, the input-image-data representing an image including a first color, the embed-data representing an image including a second color; an inverting unit configured to invert the image represented by the embed-data, in response to meeting a predetermined condition relating to the first color and the second color; and an output-image-data generating unit configured to embed, in the input-image-data, embed-data representing the image that is inverted by the inverting unit, in order to generate output-image-data in a case where the predetermined condition is met, and configured to embed, in the input-image-data, embed-data representing the image that is not inverted by the inverting unit, in order to generate output-image-data in a case where the predetermined condition is not met.

A digital medium environment includes an asset processing application that performs editing of a watermarked asset. An improved asset editing method implemented by the asset processing application comprises receiving a watermarked asset, receiving edits to the watermarked asset, storing metadata corresponding to the edits together with an asset identification (ID), communicating the metadata and asset ID, applying edits using the metadata to an unwatermarked version of the asset retrieved using the asset ID, adding a watermark back to the edited asset, and providing the edited, watermarked asset.

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.

The present disclosure relates generally to image signal processing, including encoding signals for image data or artwork. A color blend/print model is used to predict signal detectability and visibility as is printed on a particular substrate, which facilitates object grading prior to print runs.

In an example method, a first dot pattern of shadow dots and second dot pattern of highlight dots is generated. The first dot pattern and second dot pattern include information to be encoded across the image. The first dot pattern and the second dot pattern are mapped to a corresponding subset of the greyscale source pixels, the greyscale source pixels corresponding to an image to be printed. A value of a greyscale pixel in the subset of the greyscale source pixels is modified based on a predetermined threshold pixel value. The value of the greyscale pixel is set to a highlight dot value in response to detecting that the predetermined threshold pixel value is exceeded or set to a shadow dot value in response to detecting that the predetermined threshold value is not exceeded. The image including the subset of pixels with modified values is printed.