depends slibtool LIBTOOL=slibtool-shared &&
optional_depends GIFLIB   '' '--without-giflib' 'GIF support' &&
optional_depends JPEG     '' '--without-jpeg' 'JPEG support' &&
optional_depends libpng   '' '--without-libpng' 'PNG support' &&
optional_depends libwebp  '' '--without-libwebp' 'WebP support' &&
optional_depends openjpeg '' '--without-libopenjpeg' 'OpenJPEG support' &&
optional_depends tiff     '' '--without-libtiff' 'TIFF support' &&
optional_depends zlib     '' '--without-zlib' 'Zlib compression'
