getImageDimensions()

README.md

getImageDimensions TypeScript function using Image constructor and onLoad/onError. Much faster than Window.createImageBitmap. Uses imageOrientation = "from-image" to set width and height based on Exif data.

getImageDimensions.ts

const getImageDimensions = async (image: Blob | MediaSource) => {
  return new Promise((resolve, reject) => {
    const imageElement = new Image();
    imageElement.style.imageOrientation = "from-image";
    const objectUrl = URL.createObjectURL(image);

    imageElement.onload = () => {
      URL.revokeObjectURL(objectUrl);
      resolve({
        width: imageElement.naturalWidth,
        height: imageElement.naturalHeight,
      });
    };
    imageElement.onerror = (event, _, __, ___, error) => {
      URL.revokeObjectURL(objectUrl);
      reject(
        error !== undefined ? error
        : typeof event === "string" ? new Error(event)
        : new Error("Unknown error"),
      );
    };
  });
};

export { getImageDimensions };