如何使用javascript从图像中删除EXIF数据?

时间：2021-08-13 09:46:46

I read in a file from an HTML file input. For iOS I can take a picture from the camera. The problem is that if you take the picture with the camera the content will include EXIF data(at least if I read the file content with the FileReader API).

我从一个HTML文件输入的文件中读取。对于iOS，我可以用相机拍照。问题是，如果你用相机拍照，内容将包括EXIF数据(至少如果我用FileReader API读取文件内容)。

I can't use canvas cropping if the image includes EXIF data. Because the image get destroyed every time I call .toDataURL(). My guess is it doesn't recognize EXIF data and don't know how to crop a image with EXIF data.

如果图像包含EXIF数据，我就不能使用画布裁剪。因为每次调用. todataurl()时，图像都会被销毁。我猜它不认识EXIF数据，也不知道如何用EXIF数据裁剪图像。

The file content is being base64 encoded by FileReader.readAsDataURL(). And I insert it into img.src.

文件内容是由FileReader.readAsDataURL()编码的base64。我把它插入img。src。

The cropping is done by drawing a new image with ctx.drawImage(...) based in the old image and I finally got the new image data with c.toDataURL().

裁剪是通过基于旧图像的ctx.drawImage(…)绘制新的图像来完成的，最后我用c.toDataURL()获得新的图像数据。

So my question how do I remove EXIF data using javascript?

我的问题是如何使用javascript删除EXIF数据?

1 个解决方案

#1

5  

Note, you wrote:

请注意,您写道:

the image get destroyed

的形象被破坏

I think that problem is not in EXIF data. I think you have the iOS canvas limitation:

我认为问题不在EXIF数据中。我认为你有iOS的canvas限制:

The maximum size for a canvas element is 3 megapixels for devices with less than 256 MB RAM and 5 megapixels for devices with greater or equal than 256 MB RAM.

canvas元素的最大大小是小于256兆RAM的设备的300万像素，大于或等于256兆RAM的设备的500万像素。

This limits don't throw any errors, so then you will try to render or read 6MB image you will get a broken blob/dataURL string and so on. And you will think that File API is broken, canvas methods toDataURL/toBlob are broken, and you will be right. But bugs aren't in browser, this is a system limitation.

这个限制不会抛出任何错误，因此，您将尝试呈现或读取6MB的图像，您将得到一个破损的blob/dataURL字符串，等等。你会认为文件API被破坏了，画布方法toDataURL/toBlob被破坏了，你是对的。但是bug不在浏览器中，这是系统的限制。

There known libs that fix iOS limitations:

有一些已知的libs可以修复iOS的局限性:

#1

5  

Note, you wrote:

请注意,您写道:

the image get destroyed

的形象被破坏

I think that problem is not in EXIF data. I think you have the iOS canvas limitation:

我认为问题不在EXIF数据中。我认为你有iOS的canvas限制:

The maximum size for a canvas element is 3 megapixels for devices with less than 256 MB RAM and 5 megapixels for devices with greater or equal than 256 MB RAM.

canvas元素的最大大小是小于256兆RAM的设备的300万像素，大于或等于256兆RAM的设备的500万像素。

This limits don't throw any errors, so then you will try to render or read 6MB image you will get a broken blob/dataURL string and so on. And you will think that File API is broken, canvas methods toDataURL/toBlob are broken, and you will be right. But bugs aren't in browser, this is a system limitation.

这个限制不会抛出任何错误，因此，您将尝试呈现或读取6MB的图像，您将得到一个破损的blob/dataURL字符串，等等。你会认为文件API被破坏了，画布方法toDataURL/toBlob被破坏了，你是对的。但是bug不在浏览器中，这是系统的限制。

There known libs that fix iOS limitations:

有一些已知的libs可以修复iOS的局限性:

标签：

相关文章