在javascript中将图像转换为二进制数据 [英] Convert an image into binary data in javascript

问题描述

可能重复：

使用Javascript获取图像数据？

如何在HTML文件中编码图像数据？

有没有办法在javascript中将图像转换为二进制数据，反之亦然。

Is there any way to convert an image to binary data in javascript and vice versa.

推荐答案

我认为用JavaScript获取图像数据？回答你的问题：

// Code taken from MatthewCrumley (https://stackoverflow.com/a/934925/298479)
function getBase64Image(img) {
    // Create an empty canvas element
    var canvas = document.createElement("canvas");
    canvas.width = img.width;
    canvas.height = img.height;

    // Copy the image contents to the canvas
    var ctx = canvas.getContext("2d");
    ctx.drawImage(img, 0, 0);

    // Get the data-URL formatted image
    // Firefox supports PNG and JPEG. You could check img.src to guess the
    // original format, but be aware the using "image/jpg" will re-encode the image.
    var dataURL = canvas.toDataURL("image/png");

    return dataURL.replace(/^data:image\/(png|jpg);base64,/, "");
}

传递 img 标记到此功能。它将以base64编码返回图像。它将被重新编码。因此您无法访问原始图像数据。

Pass the img tag to this function. It will return the image in base64 encoding. It will be re-encoded though. So you cannot access the original image data.

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