img_resize.ts

async fn_inserir_pic_pessoal() {
    const image = await Plugins.Camera.getPhoto({
      quality: 50,
      allowEditing: false,
      resultType: CameraResultType.DataUrl,
      source: CameraSource.Prompt
    });

    this.fn_resize_img(image.dataUrl, 1024, 1024, 0.5, f => {
      this.data_profile.user_pic = f
    })
}

public fn_resize_img(img, MAX_WIDTH: number = 640, MAX_HEIGHT: number = 640, quality: number = 1, callback) {
        var canvas: any = document.createElement("canvas");
        var image = new Image();

        image.onload = () => {
            var width = image.width;
            var height = image.height;

            if (width > height) {
                if (width > MAX_WIDTH) {
                    height *= MAX_WIDTH / width;
                    width = MAX_WIDTH;
                }
            } else {
                if (height > MAX_HEIGHT) {
                    width *= MAX_HEIGHT / height;
                    height = MAX_HEIGHT;
                }
            }
            canvas.width = width;
            canvas.height = height;
            var ctx = canvas.getContext("2d");

            ctx.drawImage(image, 0, 0, width, height);

            // IMPORTANT: 'jpeg' NOT 'jpg'
            var dataUrl = canvas.toDataURL('image/jpeg', quality);

            callback(dataUrl)
        }
        image.src = img;
}