Encoding/decoding message by selectively adjusting characteristics of sub-units in image data

摘要

A message can be encoded in an image file by mapping at least one bit of the message onto each sub-unit of the image file, and adjusting a distinguishable characteristic of each sub-unit according to the corresponding bit to produce a modified image file. The message can be decoded from the message file by comparing each sub-unit of the modified image file with a corresponding sub-unit of the original image file, and identifying at least one bit of the message based on each comparison.

主权项

1. A method, comprising:
identifying multiple sub-units of an original image file, each of the sub-units comprising multiple pixels; mapping a message onto the original image file by mapping at least one bit of the message onto each of the sub-units; selectively adjusting a distinguishable characteristic of each sub-unit among the multiple sub-units according to the corresponding at least one bit to produce an adjusted image file; and storing the original image file and subsequently retrieving the message by comparing the stored original image file to the adjusted image file, wherein the distinguishable characteristic is average brightness, and wherein said selectively adjusting the distinguishable characteristic comprises increasing or decreasing the average brightness of sub-units in relation to an average brightness of the original image file where the corresponding at least one bit has a first value, and maintaining the average brightness of sub-units at a current level where the corresponding at least one bit has a second value.