Photoshop 不支持编辑钞票图片吗？ 第1页

吐槽一个：好好读一下Wiki会死吗？

链接：

欧姆龙环是防止复印或者打印的，检验模块是植入打印机、复印机固件里的，没有明确资料表明photoshop等软件会检查它，Wiki上说的清清楚楚：

较新版本的图像编辑软件，例如Adobe Photoshop和Corel PaintShop Pro软件会拒绝打印钞票 。根据http://Wired.com，伪造防治系统 （CDS，Counterfeit Deterrence System），是由中央银行伪造防治组设计，并提供给诸如Adobe等公司的二进制模块，使钞票的检测代码包含在在这些程序中。[5]不过，史蒂芬J.默多克等人的实验表明，这一钞票检测代码并不依赖于EURion模式。[6] 它采用嵌入数字水印方式，这一方法由Digimarc公司开发。[7]

我问了一下做过打印机的同事，确实有这个东西，但不是所有打印机都有，一般喷墨的都没有（当时，大概是2010年附近），那些普通的喷墨打印机打出来的东西一沾水就完蛋了，就算有人用它打印假币，也很容易被识别出来。只有高端打印机、复印机才有，有些高端的东西卖出去都有备案的……

所以，说欧姆龙环的都说错了，统统给你们点反对。

目前看到的回答里，就

说的对，目前Adobe公司用的匹配算法并未公开，所以RMB可编辑是对的，甚至在低端设备上打印也是对的。

而且题主给的1美元是旧版的，旧版1美元根本就没欧姆龙环，新版的才有这东西，我亲自验证了一下（2009版100$有，之前的版本都没有），所以，显然Adobe用的不是欧姆龙环。

关于Adobe软件用的什么算法，这个链接：

，说的很详细。并且这些验证机制也只在较新版本（没条件验证具体是哪个版本）的PS上才有，并且可能与图像的清晰度有关。

鉴于很多同学访问这个网站比较慢，我把网站的一部分内容扒下了给你们看：

UK Pounds

This image, from the 10 Pound note contains all the Eurion instances that are known of, but is not detected as currency: （包含欧姆龙环的图像，不被认为是货币）

However this image, which has one extra column of pixels at the right is detected as currency: （比前一个图多了一列像素，被识别为货币）
Even if the constellations are blanked out: （即使是欧姆龙环被屏蔽了）

所以显然啊，模式匹配的东西不是欧姆龙环。

US Dollars

Similar results can also be seen with the new US $20, in which the "0"s of the yellow "20"s scattered in the background form Eurion constellations.

Both PSP and Photoshop identify this image (from an Adobe Forum discussion) as being currency and refuse to open it, despite there being no instance of the Eurion constellation:

Another interesting property of this image is that it seems to be a near minimal test case, since if any changes are made, then it is no longer detected as currency. Even cropping away the black border will result in it opening in PSP and Photoshop CS without any warning:

It is belived that some printers use histograms to detect currency. If this is the feature used by PSP/Photoshop then removing the black border could sufficiently change the histogram to circumvent the detection system. However, this image, which is a tiled version of the first image, is not detected as currency, despite having the same histogram:

大概意思：第一个图被识别为货币，第二个不是，第三个也不是。

Detection Code

The detection code of both PSP and Photoshop CS appears to be the same, due to them having the same edge cases. A static dissasembly reveals the string "DMRC" in symbols, the stock sticker code for Digimarc, a company specialising in watermarking. Subsequent news articles have confirmed that Digimarc developed the currency-detection code, on behalf of the Central Bank Counterfeit Deterrence Group (CBCDG), part of the G11 organisation). According to Adobe and Jasc, adding the detection code is "optional" and that they do not get access to the source code or details of the algorithm.

It seems that the algorithm is optimised to err on the side of false negatives, and I have not been able to generate a false positive. It has been reported that generating a false negative is easy, perhaps as simple as using images of two notes, side-by-side, rather than just one. A statement from Adobe said that the version included in Photoshop CS was not the first one proposed by the CBCDG, and previous revisions were rejected on the basis of having an unnaceptable false positive rate. Also, while dissasembly is difficult, it is likely to be comparatively easy to patch around the call to the detection code and bypass the detector.

Another observation is that unmodified banknotes images cause the error message to be displayed after a short time, also non-banknote images open quickly. However the edge cases made from modified banknote images take a few extra seconds before either opening or displaying the error message.

This would suggest that there is a series of tests, each of which provides a score on how much the image looks like a banknote, with the later ones which take longer to execute and presumably being more accurate. At each stage there could be is a upper and lower limit on the cumulative score, if the upper bound is reached the image is not opened and an error message displayed, if the lower bound is reached then the image is opened and no further tests are performed, otherwise the next test is executed.

一种被称为"DMRC"（没有正式的名字）技术用来识别货币。这种技术是可选的（“optional”），源码未公开。

Strongly Detected Regions

The image below shows the smallest square starting at each point on an English £20 note, which is still detected as currency. The starting points are generated at 500 pixel intervals and the size of each crop is calculated to a precision of 5 pixels. Starting points are marked by a green dot, end points by a red dot; the colour of the square is of no significance. Only the crops smaller than 700x700 have been drawn. The resulting image has been converted from PPM to PNG and scaled down from 3524x1906 to 800x433 for presentation.

大概的意思是上图的几个区域都是检测点。

后面还有各种实验来避免被检测出来，包括模糊处理，旋转之类的动作，因为太多了我就不贴了。

总结一下就是：

1、PS检测钞票用的不是欧姆龙环；

2、是什么不知道，未公开算法，没有官方名称；

3、软件是否支持是可选的；

4、欧姆龙环限制高端打印复印设备；

5、算法可以被某些处理（模糊、压缩、旋转等）给绕过。