Methods and arrangements for identifying objects

A method comprising:

• receiving imagery representing two packaged items from a digital camera, each of the packaged items including digital watermarking hidden in packaging on the items;
• using one or more programmed electronic processors, analyzing the imagery to detect the digital watermarking;
• accessing a spatial template associated with the digital watermarking when two or more watermarks are detected in a signal image frame;
• comparing spatial areas containing watermarks to the spatial template;
• carrying out an action based on said comparing.

A method utilized at a retail checkout location comprising:

• receiving imagery representing a packaged item from a digital camera, the packaged item including digital watermarking hidden on its packaging, the packaged item moving relative to the digital camera;
• determining a region in the imagery corresponding to at least one relatively faster moving object;
• arranging watermark detection blocks over the determined region;
• and
• analyzing data representing imagery from within the watermark detection blocks to detect the digital watermarking.

A method of checking out groceries comprising:

• projecting or illuminating a conveyor belt moving packaged grocery items, the projection or illumination comprises a digital watermark orientation component;
• capturing imagery of the projected or illumination grocery items with a digital camera;
• using one or more programmed electronic processors, analyzing the captured imagery to discern the projected or illuminated watermark orientation component;
• and
• making a determining regarding a relative depth or orientation of packaged grocery items that are depicted in the captured imagery based on at least said analyzing.

A method utilized at a retail checkout location comprising:

• obtaining training information associated with a cashier, the training information being associated with checkout characteristics of the cashier;
• receiving imagery representing a packaged item from a digital camera, the packaged item including digital watermarking hidden on its packaging, the packaged item moving relative to the digital camera;
• adjusting a digital watermark detector based on the training information;
• and
• detecting the digital watermarking with the adjusted digital watermark detector.