How to convert tiff images from RGB color to CMYK color on Linux?

I have a poster to be submitted to the publisher which requires image files in CMYK color. The file I already have is in RGB color. How to convert it on Linux? The convert tool from ImageMagick with option -colorspace to alternate image colorspace of images. The plain output with colorspace is quite large. So […]

How to convert .pptx slides to .jpg or .png images on Linux in command line?

How to convert .pptx slides to .jpg or .png images on Linux in command line? This following method works best for me. First, convert .pptx file to .pdf using libreoffice: libreoffice –headless –convert-to pdf file.pptx –headless makes libreoffice run in batch mode and not start the GUI. The pdf file will be named file.pdf by […]

How to detect whether an image is almost blank on Linux?

How to detect whether a .jpg image is almost blank/black on Linux? Here is a bash function that I used to detect whether an image is black on Linux: function isBlank () { mean=`convert $1 -format “%[mean]” info:` echo “$mean” } It uses ImageMagic to generate formatted image characteristics (the mean). If the mean is […]