Arijit Datta's profile - activity

The decoder should also be tolerant to scale, translation, rotation, illumination variation because user may not place the mobile phone camera perfectly vertical on the watermarked image. These schemes which you have linked are spatial domain schemes. I would prefer using frequency domain since algos should be highly robust and invisible. Its not a QR code since it is invisible. When I search the term "watermark" in opencv docs, i dont get anything. Can OpenCV library be of help? Thanks!!

Well, i am basically developing a desktop app which can embed an invisible watermark (watermark is digital data further modulated by a PN sequence) into an image. The output image is then printed. When a mobile app takes a snapshot of the watermarked image, the decoder should be able to extract the watermark data. This data has a mapping to a URL in a server. The decoder should be fast enough to open the URl for the user as soon as the snapshot is taken. Basically, the point is to embed an invisible URL in the image. Since, URLs can be long, instead of embedding an invisible URL, i thought of embedding digital data and keeping the URL mapping in a server. Any other idea is welcome!

Arent there watermarking algorithms in OpenCV library? I am basically searching for robust invisible and blind watermarking algorithms for mobile commerce applications. The watermark is not a logo, its a binary data which con be mapped to a URL.