如何使Ocrad.js示例正常工作 [英] How to get Ocrad.js example to work
问题描述
我正在制作OCR(光学字符识别)Web应用程序，并且找到了JavaScript库 Ocrad.js ，这正是我一直在寻找的东西，但是我无法使它正常工作.有人可以帮我吗?
I am making an OCR (optical character recognition) web application, and I found the JavaScript library Ocrad.js, which is exactly what I was looking for, but I can't get it to work. Can somebody help me?
这是我的代码:
<!doctype html>
<html>
<head>
<script src="ocrad.js"></script>
<script src="http://ajax.googleapis.com/ajax/libs/webfont/1/webfont.js"></script>
<script src="http://code.jquery.com/jquery-1.10.2.js"></script>
<script>
$(document).ready(function() {
var image = document.getElementById('image');
var string = OCRAD(image);
alert(string);
});
</script>
</head>
<body>
<img src="img.jpg" id="image">
</body>
</html>
推荐答案
您不能仅将<img>元素传递给OCRAD()函数.
You can't just pass an <img> element to the OCRAD() function.
来自 Ocrad.js文档:
此文件公开了单个全局函数OCRAD，该函数需要 图片作为参数，并以字符串形式返回识别的文本. [...]
image参数可以是canvas元素，Context2D 实例或ImageData的实例.
This file exposes a single global function, OCRAD which takes an image as an argument and returns the recognized text as a string. [...] The
imageargument can be a canvas element, a Context2D instance, or an instance of ImageData.
尝试一下:
$(document).ready(function() {
var $img = $('#image');
var context = document.createElement('canvas').getContext('2d');
context.drawImage($img[0], 0, 0);
var imageData = context.getImageData(0, 0, $img.width(), $img.height());
var string = OCRAD(imageData);
alert(string);
});
但是您可能必须在<img>元素上放置width和height属性，才能使其正常工作.
But you may have to put width and height attributes on your <img> element in order for this to work.
如果尝试将<img>元素传递给OCRAD()函数，则会出现以下错误:
If you attempt to pass an <img> element to the OCRAD() function, you will get the following error:
未捕获的异常:5264272-异常捕获已禁用，这 无法捕获异常.用-s编译 要赶上DISABLE_EXCEPTION_CATCHING = 0或DISABLE_EXCEPTION_CATCHING = 2.
uncaught exception: 5264272 - Exception catching is disabled, this exception cannot be caught. Compile with -s DISABLE_EXCEPTION_CATCHING=0 or DISABLE_EXCEPTION_CATCHING=2 to catch.
如果尝试将jQuery对象传递给OCRAD()函数，则会出现以下错误:
If you attempt to pass a jQuery object to the OCRAD() function, you will get the following error:
错误:参数无效
Error: invalid arguments
注意:由于具有相同的来源策略，如果图像的URL与所在页面的域不同，则对context.getImageData()的调用将引发SecurityError.
Note: Because of the Same Origin Policy, the call to context.getImageData() will throw a SecurityError if the URL for the image does not have the same domain as the page it is on.
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