Holding down the alt key and clicking the left mouse button can remove a large number of black spots in the plain text pdf file scanned in black and white. Photoshop mainly deals with digital images composed of pixels. With its numerous editing and drawing tools, you can edit pictures effectively. Ps has many functions, including pictures, graphics, text, video, publishing and so on.

PDF is a portable document format and electronic file format. This file format has nothing to do with the operating system platform, that is, PDF files are common in Windows, Unix and Apple's Mac OS operating systems. This feature makes it an ideal document format for electronic document distribution and digital information dissemination on the Internet. More and more e-books, product descriptions, company announcements, online materials and emails are using PDF files.