Improved detection of JPEG 2000 code streams and added j2c file extension.
Improved detection of JPEG 2000 code streams and added j2c file extension.

kwm81/ImageMagick,UniQP/ImageMagick,Danack/ImageMagick,UniQP/ImageMagick,kwm81/ImageMagick,UniQP/ImageMagick,kwm81/ImageMagick,kwm81/ImageMagick,UniQP/ImageMagick,kwm81/ImageMagick,UniQP/ImageMagick,Danack/ImageMagick,Danack/ImageMagick,Danack/ImageMagick,Danack/ImageMagick,kwm81/ImageMagick,Danack/ImageMagick,UniQP/ImageMagick