将图像转换成二进制数据在JavaScript

Question

可能重复：
Get image data in Javascript?
How to encode image data within an HTML file?

有什么办法，以将图像转换为JavaScript和反之亦然的二进制数据。

Answer 1

我觉得Get image data in JavaScript?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标签此功能。它将以base64编码返回图像。它将被重新编码。所以你不能访问原始图像数据。