Method of embedding watermark data in an image by adjusting a pixel when color channel values are above or below a threshold and based on a pixel of a transformed noise-based image being white or black
Provided is a method of embedding and extracting watermark data that is robust against geometric distortion and low-quality photographing and for which the probability of successfully extracting watermark data for an original image is high, while the probability of successfully extracting the watermark data in the case of unauthorized copying is seriously impaired. The data embedding method according to an embodiment of the present invention comprises a step of converting the noise-based image using watermark data, and a step of adjusting the original image using the converted noise-based image.
1. A method for embedding watermark data in an original image, the data embedding method comprising the step of:
adjusting a first pixel only when a R channel value, a G channel value, and a B channel value of the first pixel of the original image exceed or fall short of a threshold value;
wherein, the first pixel is adjusted:
if a second pixel of a transformed noise-based image is white; and
by a second rule different from a first rule if the second pixel is black;
wherein, the first pixel and the second pixel correspond to a position in the original image.
2. The data embedding method of claim 1 , wherein the step of adjusting a first pixel comprises the steps of:
decreasing the R channel value of the first pixel,
increasing the G channel value, and
decreasing the B channel value.
3. The data embedding method of claim 1 , wherein the step of adjusting a first pixel comprises the steps of:
increasing the R channel value of the first pixel,
decreasing the G channel value, and
increasing the B channel value.