ImageMagick将pdf转换为图像，转换页数

i want to learn how many pages will be converted with ImageMagick command.

我想学习使用ImageMagick命令转换多少页面。

convert -density 150 -quality 100 -resize 800x "new.pdf" "pdtoimg.jpg"

It returns 6 pages with name of pdtoimg-0.jpg to pdtoimg-5.jpg.

它将pdtoimg-0.jpg的6页返回到pdtoimg-5.jpg。

is there any way to learn how many pages are in a pdf, or can I make it write the converted page names to an array?

有什么方法可以了解pdf中有多少页面，还是可以让它将转换后的页面名称写入数组？

If I want to take folder size, I have to wait all processing has ended.

如果我想拿文件夹大小，我必须等待所有处理已经结束。

1 个解决方案

#1

You could use identify. This is also one of the ImageMagick commands.

你可以使用识别。这也是ImageMagick命令之一。

identify file.pdf
identify -format "%f: %n\n" file.pdf

But for PDFs, this can be quite slow (because ImageMagick needs to use Ghostscript as a delegate for PDF processing, and Ghostscript needs to do a complete interpretation of the PDF before IM will be able to spit out the info you are interested in).

但是对于PDF来说，这可能会非常慢（因为ImageMagick需要使用Ghostscript作为PDF处理的委托，并且Ghostscript需要在IM能够吐出您感兴趣的信息之前对PDF进行完整的解释）。

So much faster would be to use an external tool, which does not read in the complete PDF, but only evaluates its metadata object:

如此快得多的是使用外部工具，它不会读取完整的PDF，但只评估其元数据对象：

pdfinfo file.pdf
pdfinfo file.pdf | grep Pages:
pdfinfo file.pdf | grep Pages: | awk '{print $2}'

pdfinfo is a tool available as part of the XPDF package or as part of the Poppler utilities (both available for Linux, Mac OS X and Windows).

pdfinfo是一个工具，可作为XPDF包的一部分或作为Poppler实用程序的一部分（可用于Linux，Mac OS X和Windows）。

#1