PHP7.3使用Imagick将PDF转图片出现UnableToOpenBlob错误如何解决

问题复现 #

在PHP 7.3环境下使用Imagick实现PDF转图片功能时，运行如下代码：

$im = new Imagick();
$im->readimage('test.pdf'); 

收到报错信息：

Fatal error: Uncaught ImagickException: UnableToOpenBlob 'test.pdf': No such file or directory @ error/blob.c/OpenBlob/3315 in C:\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\pdf_to_img.php:40 Stack trace: #0 C:\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\pdf_to_img.php(40): Imagick->readImage('test.pdf') #1 {main} thrown in C:\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\pdf_to_img.php on line 40

改用绝对路径C:\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\test.pdf后，再次出现新报错：
调整后的代码：

$im = new Imagick();
$im->readimage('C:\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\test.pdf'); 

新报错信息：

Uncaught ImagickException: PDFDelegateFailed `The system cannot find the file specified. ' @ error/pdf.c/ReadPDFImage/794 in C:\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\pdf_to_img.php:41 Stack trace: #0 C:\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\pdf_to_img.php(41): Imagick->readImage('C:\\xampp\\htdocs...') #1 {main} thrown in C:\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\pdf_to_img.php on line 41

运行环境 #

• Windows 10
• XAMPP
• PHP 7.3.27 (cli) (built: Feb 2 2021 20:46:26) ( ZTS MSVC15 (Visual C++ 2017) x64 )
• 线程安全（Thread Safety）已启用
• 架构为x64

解决方法 #

该问题由Windows系统路径反斜杠转义规则导致，仅需要对路径首尾段的反斜杠进行转义即可，调整后代码如下：

$im->readimage("C:\\xampp\htdocs\My codes\cURLs\php-curl-class\PDFs\\test.pdf");

内容的提问来源于stack exchange，提问作者Siya