Interpolation and file size
Posted: Tue Nov 11, 2003 10:42 am
I'm looking for a converter to make thumbnails for my web page. I tried both xn and abc (advanced batch converter) and found xnconvert generate much more larger jpg files. For example, a 760kB 1600x1200 jpg => 120 width thumbnail jpg, will result 140~200kB in xn with 10~30 quality level, but only 3kB in abc with default quality level and bspline interpolation. And furthermore, the converted picture looks much nicer than xn!!
I use below command for xn:
nconvert -quiet -q 30 -opthuff -ratio -rflag decr -rtype linear -o d:\tmp\test1.jpg -truecolors -resize 120 -out jpeg "d:\tmp\big.jpg"
and this for abc:
abc.exe "d:\tmp\big.jpg" /reduce=(120,0,4) /convert=d:\tmp\test2.jpg
Why there's a so big gap? Does interpolation influence file size so much?
I use below command for xn:
nconvert -quiet -q 30 -opthuff -ratio -rflag decr -rtype linear -o d:\tmp\test1.jpg -truecolors -resize 120 -out jpeg "d:\tmp\big.jpg"
and this for abc:
abc.exe "d:\tmp\big.jpg" /reduce=(120,0,4) /convert=d:\tmp\test2.jpg
Why there's a so big gap? Does interpolation influence file size so much?