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SignMyImage

Protect your images from copying by invisible watermarking.

Invisible Watermarking - Signature Properties

Signature invisibility

The signature is inserted into the blue channel of the image. This causes slight changes in the image’s blue channel, but the changes are invisible to the human eye. Compare the signed and unsigned image below.


Original image	Signed image

Signature durability

1. Original images


Image 1 - A cave	Image 2 - Cliffs	Image 3 - An icefall

Image 4 - Teotihuacan	Image 5 - Alps	Image 6 - African goats

2. Signed images


signed & DETECTED	signed & DETECTED	signed & DETECTED

signed & DETECTED	signed & DETECTED	signed & DETECTED

2. Image cropping

In order for the sign to remain intact after image cropping, it is placed in several areas of the image. SignMyImage can only detect the sign if at least one (entire) area where the sign has been placed remains in the cropped image. The number of rectangles varies from one to five depending on the nature of the image.

3. Jpeg compressed images

In order to test the stability of the sign after image compression, we took signed images and saved them as jpegs of varying quality. All of the JPEGs were then checked for sign detection.


jpeg 95% - DETECTED	jpeg 90% - DETECTED	jpeg 85% - DETECTED

jpeg 80% - DETECTED	jpeg 75% - DETECTED	jpeg 70% - DETECTED

jpeg 65% - DETECTED	jpeg 60% - DETECTED

jpeg 95% - DETECTED	jpeg 90% - DETECTED	jpeg 85% - DETECTED

jpeg 80% - DETECTED	jpeg 75% - DETECTED	jpeg 70% - DETECTED

jpeg 65% - DETECTED	jpeg 60% - DETECTED

jpeg 95% - DETECTED	jpeg 90% - DETECTED	jpeg 85% - DETECTED

jpeg 80% - DETECTED	jpeg 75% - DETECTED	jpeg 70% - DETECTED

jpeg 65% - NOT DETECTED	jpeg 60% - NOT DETECTED

jpeg 95% - DETECTED	jpeg 90% - DETECTED	jpeg 85% - DETECTED

jpeg 80% - DETECTED	jpeg 75% - DETECTED	jpeg 70% - DETECTED

jpeg 65% - DETECTED	jpeg 60% - DETECTED

jpeg 95% - DETECTED	jpeg 90% - DETECTED	jpeg 85% - DETECTED

jpeg 80% - DETECTED	jpeg 75% - DETECTED	jpeg 70% - DETECTED

jpeg 65% - DETECTED	jpeg 60% - DETECTED

jpeg 95% - DETECTED	jpeg 90% - DETECTED	jpeg 85% - DETECTED

jpeg 80% - DETECTED	jpeg 75% - DETECTED	jpeg 70% - DETECTED

jpeg 65% - DETECTED	jpeg 60% - DETECTED

4. Scaled images

We took signed images and scaled them with different scaling factors from 110%(zoom up) to 42%(zoom down). Results of detection are written under images.