ImageMagick found; using ImageMagick for resizing.
org.im4java.core.CommandException: java.lang.IllegalStateException: no ImageReader for given format
        at org.im4java.core.ImageCommand.run(ImageCommand.java:219)
        at pl.asie.ctif.Utils.resize(Utils.java:81)
        at pl.asie.ctif.Main.main(Main.java:270)
Caused by: java.lang.IllegalStateException: no ImageReader for given format
        at org.im4java.core.Stream2BufferedImage.consumeOutput(Stream2BufferedImage.java:82)
        at org.im4java.process.ProcessStarter.processOutput(ProcessStarter.java:276)
        at org.im4java.process.ProcessStarter.access$200(ProcessStarter.java:54)
        at org.im4java.process.ProcessStarter$2.call(ProcessStarter.java:433)
        at java.util.concurrent.FutureTask.run(Unknown Source)
        at java.lang.Thread.run(Unknown Source)
Generating palette...
Exception in thread "main" java.lang.NullPointerException
        at pl.asie.ctif.Utils.getRGB(Utils.java:119)
        at pl.asie.ctif.PaletteGenerator.<init>(PaletteGenerator.java:46)
        at pl.asie.ctif.Main.main(Main.java:275)