code-boxx/0-JS-WATERMARK.MD

## 0-JS-WATERMARK.MD

      
    Raw
  

              0-JS-WATERMARK.MD
            
          
    JAVASCRIPT WATERMARK IMAGE

https://code-boxx.com/watermark-images-javascript/
IMAGES


LICENSE

Copyright by Code Boxx
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

  
## 1-text.html
<!DOCTYPE html>
<html>
  <head>
    <title>JS Watermark</title>
  </head>
  <body>
    <!-- (A) HTML CANVAS -->
    <canvas id="demo"></canvas>

    <script>
    // (B) IMAGE + WATERMARK + CANVAS
    var img = new Image(),
        watermark = "Copyright",
        canvas = document.getElementById("demo"),
        ctx = canvas.getContext("2d");

    // (C) ADD WATERMARK (WHEN IMAGE IS FULLY LOADED)
    img.onload = () => {
      // (C1) SET IMAGE
      canvas.width = img.naturalWidth;
      canvas.height = img.naturalHeight;
      ctx.drawImage(img, 0, 0, img.naturalWidth, img.naturalHeight);

      // (C2) ADD WATERMARK
      ctx.font = "bold 24px Arial";
      ctx.fillStyle = "rgba(255, 0, 0, 0.5)";
      ctx.fillText(watermark, 10, 30);

      // (C3) DOWNLOAD (IF YOU WANT)
      let anchor = document.createElement("a");
      anchor.href = canvas.toDataURL("image/webp");
      anchor.download = "demoA.webp";
      anchor.click();
      anchor.remove();
    };

    // (D) GO
    img.src = "source.png";
    </script>
  </body>
</html>

## 2-image.html
<!DOCTYPE html>
<html>
  <head>
    <title>JS Watermark</title>
  </head>
  <body>
    <!-- (A) HTML CANVAS -->
    <canvas id="demo"></canvas>

    <script>
    // (B) IMAGE + WATERMARK + CANVAS
    var img = new Image(),
        watermark = new Image(),
        loaded = 0,
        canvas = document.getElementById("demo"),
        ctx = canvas.getContext("2d");

    // (C) ADD WATERMARK (WHEN IMAGES ARE FULLY LOADED)
    function mark () { loaded++; if (loaded==2) {
      // (C1) SET IMAGE
      canvas.width = img.naturalWidth;
      canvas.height = img.naturalHeight;
      ctx.drawImage(img, 0, 0, img.naturalWidth, img.naturalHeight);

      // (C2) ADD WATERMARK
      ctx.drawImage(watermark, 0, 0, watermark.naturalWidth, watermark.naturalHeight);

      // (C3) DOWNLOAD (IF YOU WANT)
      let anchor = document.createElement("a");
      anchor.href = canvas.toDataURL("image/webp");
      anchor.download = "demoB.webp";
      anchor.click();
      anchor.remove();
    }}

    // (D) GO
    img.onload = mark;
    watermark.onload = mark;
    img.src = "source.png";
    watermark.src = "potato.png";
    </script>
  </body>
</html>

## 3-center.html
<!DOCTYPE html>
<html>
  <head>
    <title>JS Watermark</title>
  </head>
  <body>
    <!-- (A) HTML CANVAS -->
    <canvas id="demo"></canvas>

    <script>
    // (B) IMAGE + WATERMARK + CANVAS
    var img = new Image(),
        watermark = new Image(),
        loaded = 0,
        canvas = document.getElementById("demo"),
        ctx = canvas.getContext("2d");

    // (C) ADD WATERMARK (WHEN IMAGES ARE FULLY LOADED)
    function mark () { loaded++; if (loaded==2) {
      // (C1) SET IMAGE
      canvas.width = img.naturalWidth;
      canvas.height = img.naturalHeight;
      ctx.drawImage(img, 0, 0, img.naturalWidth, img.naturalHeight);

      // (C2) CALCULATE CENTER
      var wx = Math.floor(img.naturalWidth/2 - watermark.naturalWidth/2),
          wy = Math.floor(img.naturalHeight/2 - watermark.naturalHeight/2);

      // (C3) ADD WATERMARK
      ctx.drawImage(watermark, wx, wy, watermark.naturalWidth, watermark.naturalHeight);

      // (C4) DOWNLOAD (IF YOU WANT)
      let anchor = document.createElement("a");
      anchor.href = canvas.toDataURL("image/webp");
      anchor.download = "demoC.webp";
      anchor.click();
      anchor.remove();
    }}

    // (D) GO - PROCEED ONLY WHEN IMAGES ARE LOADED
    img.onload = mark;
    watermark.onload = mark;
    img.src = "source.png";
    watermark.src = "potato.png";
    </script>
  </body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<title>JS Watermark</title>
	</head>
	<body>
	<!-- (A) HTML CANVAS -->
	<canvas id="demo"></canvas>

	<script>
	// (B) IMAGE + WATERMARK + CANVAS
	var img = new Image(),
	watermark = "Copyright",
	canvas = document.getElementById("demo"),
	ctx = canvas.getContext("2d");

	// (C) ADD WATERMARK (WHEN IMAGE IS FULLY LOADED)
	img.onload = () => {
	// (C1) SET IMAGE
	canvas.width = img.naturalWidth;
	canvas.height = img.naturalHeight;
	ctx.drawImage(img, 0, 0, img.naturalWidth, img.naturalHeight);

	// (C2) ADD WATERMARK
	ctx.font = "bold 24px Arial";
	ctx.fillStyle = "rgba(255, 0, 0, 0.5)";
	ctx.fillText(watermark, 10, 30);

	// (C3) DOWNLOAD (IF YOU WANT)
	let anchor = document.createElement("a");
	anchor.href = canvas.toDataURL("image/webp");
	anchor.download = "demoA.webp";
	anchor.click();
	anchor.remove();
	};

	// (D) GO
	img.src = "source.png";
	</script>
	</body>
	</html>