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Showing posts from January, 2022

The trusty ImageMagick package

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  Seven years ago I made a simple script to turn a pile of scanned exams into a personalized email for each student to get their marked exams. I used our photocopy machine that doubles as a scanner to create a large PDF file containing all the exams. ImageMagick's convert, identify and mogrify commands were used within the script for several massaging of the scanned pages but, years later, using WSL instead of a Linux machine, I was shown a weird error. None of the commands seemed to be able to handle a PDF file as a source anymore: identify-im6.q16: attempt to perform an operation not allowed by the security policy `PDF' @ error/constitute.c/IsCoderAuthorized/408. Luckily, I quick search lead me to a solution: just edit /etc/ImageMagick-6/policy.xml and enable PDF use, which was disabled as a safety feature as PDF can be an attack vector. More info .

Remote development of a hardware device

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I am familiar with helping other people remotely using tools like TeamViewer. Many times it has to do with a friend having trouble with her computer, operating system, or software.  But quite recently, I took care of the development of a complete machine without ever touching it even once. The project was part of a friend's Ph.D. work about the proper tensioning of old paintings. He asked me for help with a specific need in mind. He needed a machine that could push a probe against a canvas surface while monitoring the back force generated.  As usual, there were a few more constraints, like it was needed to be used in a few weeks as an appointment was already made with an important European museum. And all the parts needed have to be available online to get quickly to my friend's residence in Rome. Fortunately, my friend can solder and wire or build a contraption, though he cannot code. So the plan was to make this happen by shipping all the parts to his apartment and he will do