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I am trying to convert a free ebook from PNG to JPG, so I can read it on my Sony Bravia KDL-40R470.

This is how I converted the PNG file:

convert -density 117 -quality 80 progit.pdf progit.jpg

Unfortunately, my TV refuses to display the image. Changing density and quality makes no difference.

However, when I manually capture a screenshot in a PDF viewer, crop that screenshot in GIMP and export it to JPG with the same quality of 80, the resulting image displays just fine on my TV.

However, manually converting hundreds of pages is simply not an option for me :)

Can anybody spot potential problems in the first JPG file that would make a TV refuse to display it? Which Imagemagick options would be recommended to mitigate these problems?

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I solved the problem by using Ghostscript instead of Imagemagick:

gs -dNOPAUSE -dBATCH -sDEVICE=jpeg -dJPEGQ=90 -r117 -dTextAlphaBits=4 -tGraphicsAlphaBits=4 -sOutputFile="progit-%03d.jpg" "progit.pdf"

The resulting images consume a lot less memory now, and the image quality is awesome.

  • Within the GIMP community, we have found that many devices won't display progressive JPEG files (some controller types must have decided that this saves them 5 cent per device). I'd check if you can control that with an ImageMagick option. – Michael Schumacher Mar 30 '15 at 19:34
  • @MichaelSchumacher In the meantime, I solved the problem again, by buying a Kindle ;) – fredoverflow Mar 30 '15 at 20:20
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Your first image is CMYK which is OK from a jpeg specification standpoint, but often not supported. Try adding -colorspace RGB

other options manual

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