Not to go into too much detail but I was tasked to convert some images supplied by a forensic accounting firm for importing into one of our legacy systems.The images were in TIFF format, each containing a page of a document. All of the TIFFs in each folder belong to the same document.

My main problem is that the TIFFs would not be recognized by our importing software so I needed a quick and easy way to convert all of the images before importing.

I tried to convert these images with software such as ACDSEE which our company had purchased for this task in the past but the 22,000 images in 3000+ directories consistently crashed the computers I was running them on.  So to develop a free solution in combining ImageMagick and Powershell was fantastic!

ImageMagick is free, downloadable software from and Powershell is a scripting language from Microsoft that is available for free in windows update from XP Service 3 onwards.

Once I had ImageMagick installed, I executed the following command from my command line to convert all of my TIFFs.

After a couple of hours, the images were in a format I could use.

In a nutshell, powershell iterates over all of the TIFF files in all subdirectories and runs the mogrify command that is contained in the ImageMagick package. Mogrify modifies the file in place and overwrites the original.

Group4 is the image compression that I needed for this particular task but you could choose whatever you want.

The power of running a one line command to mass modify 22,000 files is quite powerful and I hope you Windows users find it helpful.