Ubuntu – Convert emf to PNG image using command line

generalizing from an answer answer from this forum:

convert orig_file.jpg -blur 0x8 blured_file.jpg

or

convert orig_file.jpg -filter Gaussian -blur 0x8 blured_file.jpg

where 0x8 defines radiusxsigma from the imagemagick documentation:

The Sigma value is the important argument, and determines the actual amount of blurring that will take place.

The Radius is only used to determine the size of the array which will hold the calculated Gaussian distribution. It should be an integer. If not given, or set to zero, IM will calculate the largest possible radius that will provide meaningful results for the Gaussian distribution.

The larger the Radius the radius the slower the operation is. However too small a Radius, and severe aliasing effects may result. As a guideline, Radius should be at least twice the Sigma value, though three times will produce a more accurate result.

I was able to find a solution through the ImageMagick forum.

The method was to change the settings for Resource limits in the file handling that in ImageMagick, called policy.xml. In Ubuntu 18.04 that is found in /etc/ImageMagick-6. It is set as read-only, so I temporarily changed the write permissions with sudo chmod 777 policy.xml from within that folder. After making the changes, I switched the permission to 744.

This is what the relevant section of policy.xml looks like:

<policymap>
  <!-- <policy domain="resource" name="temporary-path" value="/tmp"/> -->
  <policy domain="resource" name="memory" value="14GiB"/>
  <policy domain="resource" name="map" value="30GiB"/>
  <policy domain="resource" name="width" value="16MP"/>
  <policy domain="resource" name="height" value="16MP"/>
  <policy domain="resource" name="area" value="40GP"/>
  <policy domain="resource" name="disk" value="30GiB"/>
  <!-- <policy domain="resource" name="file" value="768"/> -->
  <!-- <policy domain="resource" name="thread" value="4"/> -->
  <!-- <policy domain="resource" name="throttle" value="0"/> -->
  <!-- <policy domain="resource" name="time" value="3600"/> -->
  <!-- <policy domain="system" name="precision" value="6"/> -->
  <!-- not needed due to the need to use explicitly by mvg: -->
  <!-- <policy domain="delegate" rights="none" pattern="MVG" /> -->
  <!-- use curl -->
  <policy domain="delegate" rights="none" pattern="URL" />
  <policy domain="delegate" rights="none" pattern="HTTPS" />
  <policy domain="delegate" rights="none" pattern="HTTP" />
  <!-- in order to avoid to get image with password text -->
  <policy domain="path" rights="none" pattern="@*"/>
  <policy domain="cache" name="shared-secret" value="passphrase" stealth="true"/>
</policymap>

The parts that needed changing already have the values I substituted in so I can process the image in question. They are the 3rd to the 8th line, the resource named "memory" to the resource named "disk".

After making those changes, checking in the terminal with identify -list resource returns the new values.