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How to find the original size of an Image using FabricJS?

FabricJS Javascript HTML5 Canvas

In this tutorial, we are going to learn how to find the original size of an Image using FabricJS. We can create an Image object by creating an instance of fabric.Image. Since it is one of the basic elements of FabricJS, we can also easily customize it by applying properties like angle, opacity etc. In order to find the original size of an Image, we use the getOriginalSize method.

Syntax

getOriginalSize(): Object

Return Value

The method returns an object containing the width and height of the original image in pixels:

{
    width: number,
    height: number
}

Using the getOriginalSize Method

In this example, we have used the getOriginalSize method to obtain the width and height values of the image. Here, the width and height values being returned are 311 and 82 respectively.

<!DOCTYPE html>
<html>
<head>
   <!-- Adding the Fabric JS Library-->
   <script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
</head>
<body>
   <h2>Using the getOriginalSize method</h2>
   <p>
      You can open the console from dev tools to see that the logged output contains the height and width of the Image
   </p>
   <canvas id="canvas"></canvas>
   <img src="https://www.tutorialspoint.com/images/logo.png" id="img1" style="display: none" />
   <script>
      // Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas");
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);
      
      // Initiating the image element
      var imageElement = document.getElementById("img1");
      
      // Initiate an Image object
      var image = new fabric.Image(imageElement, {
         top: 50,
         left: 110,
         skewX: 15,
      });
      
      // Add it to the canvas
      canvas.add(image);
      
      // Using the getOriginalSize method
      console.log(
         "The original size of the Image object is: ",
         image.getOriginalSize()
      );
   </script>
</body>
</html>

The original size of the Image object is: {width: 311, height: 82}

Using the getOriginalSize Method with cropX Property

Let's see a code example of the logged output when the getOriginalSize method is used in conjunction with the cropX property. Here, we have passed a value of 50 to cropX. Due to this, our Image object will have a 50px crop from the original image size in the x-direction. However, when we use the getOriginalSize method we are returned the width and height values as 311 and 82 respectively which proves that getOriginalSize will only return the original size of the image, regardless of transformations.

<!DOCTYPE html>
<html>
<head>
   <!-- Adding the Fabric JS Library-->
   <script src="https://cdnjs.cloudflare.com/ajax/libs/fabric.js/510/fabric.min.js"></script>
</head>
<body>
   <h2>Using the getOriginalSize method along with cropX property</h2>
   <p>
      You can open the console from dev tools to see that the original size of the image will be returned regardless of having applied image cropping in x-direction
   </p>
   <canvas id="canvas"></canvas>
   <img
      src="https://www.tutorialspoint.com/images/logo.png"
      id="img1"
      style="display: none"
   />
   <script>
      // Initiate a canvas instance
      var canvas = new fabric.Canvas("canvas");
      canvas.setWidth(document.body.scrollWidth);
      canvas.setHeight(250);
      
      // Initiating the image element
      var imageElement = document.getElementById("img1");
      
      // Initiate an Image object
      var image = new fabric.Image(imageElement, {
         top: 50,
         left: 110,
         skewX: 15,
         cropX: 50,
      });
      
      // Add it to the canvas
      canvas.add(image);
      
      // Using the getOriginalSize method
      console.log(
         "The original size of the Image object is: ",
         image.getOriginalSize()
      );
   </script>
</body>
</html>

The original size of the Image object is: {width: 311, height: 82}

Key Points

  • The getOriginalSize() method returns the dimensions of the source image, not the current rendered size
  • Transformations like scaling, cropping, or skewing don't affect the returned values
  • This method is useful when you need to reset an image to its original dimensions
  • The returned object contains width and height properties as numbers

Conclusion

The getOriginalSize() method in FabricJS provides a reliable way to retrieve the original dimensions of an image, regardless of any transformations applied. This is particularly useful for resetting images or calculating aspect ratios based on the source dimensions.

Updated on: 2026-03-15T23:19:00+05:30

1K+ Views

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