ImageMagick的`convert`实用程序占用PDF输入的“太多”内存

我经常使用ImageMagick的convert*-> PNG转换，但是当PDF超过50页时– convert占用的内存超过3 Gib（!!!）。我想它首先加载了所有内容。

那是不可接受的。它应该一页一页地阅读PDF，为什么立刻全部阅读！

也许有一种方法可以调整它？还是任何好的替代品？

解决了以下问题：

cat <<EOF > /etc/profile.d/ImageMagick.sh
# Set ImageMagick memory limits: it eats too much
export MAGICK_MEMORY_LIMIT=1024 # Use up to *MB of memory before doing mmap
export MAGICK_MAP_LIMIT=1024    # Use up to *MB mmaps before caching to disk
export MAGICK_AREA_LIMIT=4096   # Use up to *MB disk space before failure
export MAGICK_FILES_LIMIT=1024  # Don't open more than *file handles
EOF

您是否尝试过缓存？

从手册页

缓存阈值

      megabytes of memory available to the pixel cache.

      Image pixels are stored in memory until 80 megabytes of
      memory have been consumed.  Subsequent pixel operations

      are cached on disk.  Operations to memory are  significantly 
      faster but if your computer does not have a sufficient 
      amount of free memory you may  want  to  adjust
      this threshold value.

我正在使用以下内容：

convert -limit memory 64 -limit map 128 original.djvu newfile.pdf

我的主驱动器空间有限，因此我要在变量前添加

env MAGICK_TMPDIR=/host/Temp convert -limit memory 64 -limit map 128 original.djvu newfile.pdf