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This article focuses on "how to use canvas to achieve blind watermark encryption and decryption", interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn how to use canvas to encrypt and decrypt blind watermarks.

Here is the code to add a blind watermark to the image:

Var canvas = document.getElementById ("myCanvas") var ctx = canvas.getContext ("2d") var img = new Image (); var textData,originalData; img.src ='. / codeImg.png' / / Image loading completed img.onload = function () {/ / set canvas width and height to picture width and height canvas.width = img.width Canvas.height = img.height; / / set watermark font ctx.font = '30px Microsoft Yahei'; / / since the width of the picture is fixed at 800, we need to add three watermarks to each line, adding a new watermark for every 100 pixels.

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