An object is to provide a copy function that guarantees intensity of embedded information. At the time of copying a printed material, embedded information is extracted from a scanned image obtained by scanning the target printed material. Then, in a case where it is confirmed that the copy-target printed material is an authentic document by the extracted embedded information, the embedded information extracted from the scanned image is reconfigured and printed and output.

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.

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.

Examples relating to watermarking digital content are described herein. According to one example, a digital quality of digital content received for watermarking is determined. From a library of watermark tints comprising a plurality of preformed watermark tints of predefined sizes, a watermark tint set for watermarking the digital content is retrieved, the watermark tint set comprising a plurality of watermark tints having a first size. The first size of the plurality of watermark tints is determined based on the digital quality of the digital content. The plurality of watermark tints having the first size are overlaid over the digital content to watermark the digital content.

The present disclosure relates generally to signal encoding for product packaging and other printed objects. One implementation utilizes a target reflectance value for image content combined with an encoded signal at or around 660 nm to guide color changes. Luminance change is controlled through opposing color shifts, while maintaining the target reflectance value. Other implementations are provided.

An image forming apparatus includes an image forming portion, an image reading portion, an analysis processing portion, a generation processing portion, and a printing processing portion. The image forming portion forms an image on a paper sheet. The image reading portion reads a first image from a printed side of a used paper sheet supplied from a sheet feed portion. The analysis processing portion analyzes content of the first image read by the image reading portion. The generation processing portion generates, based on the content of the first image analyzed by the analysis processing portion, a second image that degrades visibility of the first image when the second image is superimposed on the first image. The printing processing portion causes the image forming portion to execute a printing process such that the second image generated by the generation processing portion is superimposed on the first image on the printed side.

Examples relating to watermarking digital content are described herein. According to one example, a digital quality of digital content received for watermarking is determined. From a library of watermark tints comprising a plurality of preformed watermark tints of predefined sizes, a watermark tint set for watermarking the digital content is retrieved, the watermark tint set comprising a plurality of watermark tints having a first size. The first size of the plurality of watermark tints is determined based on the digital quality of the digital content. The plurality of watermark tints having the first size are overlaid over the digital content to watermark the digital content.

An image processing apparatus includes processing circuitry. The processing circuitry is configured to compose background information with latent image information to generate a latent-image-embedded image, add the latent-image-embedded image to print data, and at least one of extract the latent image information from the print data and extract the background information from the print data.

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.

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.