The meaning of photo watermarking is to leave some symbols on the photo; Photo watermarking mainly refers to some logos, information and websites left on modern digital photos, such as images, sounds and video signals. , in which some digital information is added for copyright protection. Of course, adding watermark can't affect the readability and aesthetics of the original file.

Extended data:

Usually paper money, certificates, securities, food stamps, etc. All have watermarks to prevent counterfeiting. For example, in the left margin of the 20 15 version of 100 RMB, you can see the head image through the light, which is the watermark.

The earliest watermark was created by paper makers in the Tang Dynasty in China at the end of the 8th century or the beginning of the 9th century. At that time, silk thread was woven on the bamboo curtain. The pattern is more prominent than the curtain surface, so the fiber interweaving in the corresponding parts is finer and the light transmittance is higher when making paper. The watermark effect is obtained.

/kloc-In the 3rd century, Italian craftsmen also woven letters, numbers or patterns on the paper-making network, leaving watermarks as trademarks in the paper-making industry. On the paper machine, the wet paper is pressed with decorative paper (watermark paper) to form a watermark. The decorative ring can be carved with various patterns or patterns as required.

References:

Baidu encyclopedia-watermark