Piracy used to be difficult to do. I used the lightest pound of paper, but I didn't want to add fluorescent agent. If I didn't print it, I thought it was toilet paper. This kind is usually copied by small workshops, right, copied. Books that are not too thick can even be carved with steel plates. Thicker ones have to be typed, arranged casually and printed by machine. Then tie it up and call it a day. Now piracy is getting higher and higher, at least there are not many pornographic books. And computers are cheap. Many use ocr. Just picture text information recognition (as it seems to be called). Now the quality of scanned pictures is getting higher and higher, except punctuation, the probability of typos is much smaller than before. Even some pirates can pick out typos in the original and remove them. What you said is almost inferior piracy, but now you do less. Now the pirated book market is concentrated in tb. Law enforcement can't find it. It's particularly messy. Some clearly marked prices are very low, and buyers will know that they are pirated at a glance. If they are not good, they will sell you pirated goods at normal prices. I have seen several pirated textbooks, except the paper ones, which are almost the same as the original ones. Even the fonts look slimmer and clearer. Generally speaking, there are few pirates nowadays. Although China just can't protect property rights. Moreover, writers have other difficulties in publishing books, and the price of books is extremely low, making pirated books unprofitable. Gradually, there are so many big ones. The quality is getting better and better. I don't know what to say. When reading a book, I think the typo rate that I can tolerate is at most one thousandth. According to my experience, this software is at least 5%, which is far from meeting the requirements. Okay, change it manually? This is equivalent to reading this book again, comparing it when reading, and reformulating the formula of science and engineering books. But I found that the typesetting of pirated books is basically the same as that of genuine books, even though the paper is worse and the printing is worse. So what is most likely to be leaked is a PDF manuscript or something.