对图像中的文本进行去水印. [英] De-watermarking of text from an image.

问题描述

我需要使用C#对带水印的图像进行水印处理.谁能帮助我.

I need to de watermark a watermarked image using C#. Can anyone help me for that.

推荐答案

让我们尝试从逻辑上跟踪这个问题的含义.水印用于保护图片作者的财产.如果您是作者，则始终具有原始的非水印图像. 去水印"的原因是什么?删除作者的水印.为什么?我的猜测是:为了作弊.我不会说是为了偷窃某些财产"，因为我不能百分百确定，但是我可以肯定这是作弊行为.当作者故意为图像加水印时，删除此信息将掩盖图像的属性，我称之为作弊.

我们不应该协助进行非法或至少在道德上有问题的活动.

但是，如果您证明我错了，我将非常高兴.



好，对我的Manfred的评论说这是您的水印应用程序. 但是在这种情况下，这个问题是完全没有意义的.去水印"的唯一合理方法是在对水印进行保护之前保留图像，并用原始图像替换水印图像.不仅在实践上或在大多数情况下，甚至从理论上讲，在任何情况下不可能，而且在任何合法活动中从不需要做任何事情.

我在上面解释了为什么出于任何合法目的都不需要它，现在让我解释不可能部分.
曾经听说过信息熵( http://en.wikipedia.org/wiki/Information_entropy [
即使文本几乎不可见并且只能使用您的软件显示，也无法解决此问题.更确切地说，在一些非常琐碎的水印算法的特殊情况下，可以完全恢复原始图像(简单示例:将具有固定颜色和透明度的文本与图像的中等对比度部分混合)，但是这种琐碎的算法会失败水印的目的，因此考虑它们是没有意义的.有可能设计一种不可行进行反演的水印算法，我会保证.这样做甚至没有困难.而且只有这样的算法才对水印有用.

谢谢

—SA

Let''s try to logically track the meaning of this question. Watermarking is used for protection of the property of the author of the picture. If you are the author, you always have an original non-watermarked image. What would be the reason for "de-watermarking"? Removal of the author''s watermark. Why? My guess would be: for the purpose of cheating. I don''t say "for stealing of some property", because I cannot be 100% sure, but it looks certain certain to me that it''s cheating. As the author watermarked the image on purpose, removing this information would conceal the attribution of the image, which I call cheating.

We''re not supposed to assist in illegal or at least morally questionable activity.

However, I would be quite happy if you proof me wrong.



OK, a comment to the comment my Manfred says that this is your water-marking application. But in this case, the question is completely pointless. The only reasonable way to "de-watermark" is to preserve the image before watermarking and replace a water-marked image with the original one. Not only doing anything else is practically or in most cases even theoretically impossible, but it also never needed in any legitimate activity.

I explained why it is not needed for any legitimate purpose above, now let me explain impossibility part.
Ever heard of information entropy (http://en.wikipedia.org/wiki/Information_entropy[^])? By adding a watermark you increase the entropy to the original image, so the original image cannot be restored because entropy processes are irreversible.

Consider a simple extreme example: a copyright text is made of fixed color, fully opaque. In this case, you simply replace some pixels of the original image with pixels of the text color. The original information about the replaced pixels is completely lost and cannot be restored. The "de-watermarking" software can only "reinvent" the lost pixels, which can never be done with sufficient quality in all cases. In the general case, this is plain impossible task.

Even when a text is done nearly invisible and could only be revealed using your software, it does not make this problem solvable. More exactly, in some special cases of very trivial water-marking algorithms it is possible to totally restore the original image (simple example: blending a text with fixed color and transparency with medium-contrast part of the image), but such trivial algorithms defeat the purpose of water-marking, so considering them makes no sense. It is possible to design a water-marking algorithm which is infeasible to invert, I''ll guarantee that. Doing so is not even difficult; and only such algorithms are useful for watermarking.

Thank you,

—SA

没有针对去水印"的解决方案.

There is no solution for ''De watermarking''.

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