OPTIPNG(1) OptiPNG Manual OPTIPNG(1) (NAME) optipng - Portable Network Graphics (PNG) (SYNOPSIS) optipng [] [--] (DESCRIPTION) OptiPNG PNG . (metadata) (pixmap) PNG . . PNG . . (FILES) (raster) PNG ( ) . GIF BMP PNM TIFF. OptiPNG : o PNG : (in-place) . -force . -keep . o : PNG . .png . -clobber . (OPTIONS) (General options) -?, -h, -help . -backup, -keep . -clobber . -backup . -dir directory directory. -fix . . . . . . -force . PNG ( dSIG) PNG PNG . -out file file. . -preserve ( ) . -quiet, -silent ( ). -simulate : . -v -verbose -version. -verbose (verbose). -version . -- . -o level . 0 . IDAT . 1 IDAT . OptiPNG . 2 IDAT . . -h . -f filters PNG . filters ( -f0-5) filters -o . 0 1 2 3 4 PNG (None Left Up Average Paeth) . 5 libpng(3) OptiPNG . -full IDAT . . -i type (interlace) (0-1). 0 ( ) . 1 Adam7 . . -nb . -nc . -np . -nx : -nb -nc -np . -nz IDAT . IDAT ( IDAT) . PNG . -zc levels zlib IDAT . levels ( -zc6-9) levels -o . zlib(3) OptiPNG . -zm levels zlib IDAT . levels ( -zm8-9) levels -o . zlib(3) OptiPNG . -zs strategies zlib IDAT . strategies ( -zs0-3) strategies -o . zlib(3) OptiPNG . -zw size zlib (32k,16k,8k,4k,2k,1k,512,256) IDAT . size ( 16384) ( 16k) . size IDAT 32768 . zlib(3) OptiPNG . -snip . ( ) . -strip objects PNG. PNG (chunk) tRNS . (tRNS RGBA .) -strip all . (Notes) ( --) . . (=) . (rangeset) . : optipng -out newfile.png <=> optipng -out=newfile.png optipng -o3 <=> optipng -o 3 <=> optipng -o=3 optipng -f0,3-5 <=> optipng -f 0,3-5 <=> optipng -f=0,3-5 . : optipng -f0 -f3-5 <=> optipng -f0,3-5 optipng -zs0 -zs1 -zs2,3 <=> optipng -zs0-3 (EXTENDED DESCRIPTION) PNG : 1. . ( PNG) . 2. . 3. IDAT CRC IDAT . 4. zlib IDAT PNG . . . -nb -nc -np -nx . -o -zc -zm -zs -zw . . IDAT -zw . . (EXAMPLES) optipng file.png # optipng -o5 file.png # optipng -o7 file.png # (BUGS) . ( .) : o . o . IDAT . TIFF PNG ( RGB RGBA) . . (pipes) (streams) ..SH " (SEE ALSO)" png(5), libpng(3), zlib(3), pngcrush(1), pngrewrite(1). (STANDARDS) OptiPNG PNG (<< PNG>>) PNG (<< PNG>>) . o Portable Network Graphics (PNG) Specification, Second Edition. W3C Recommendation 10 November 2003; ISO/IEC IS 15948:2003 (E). https://www.w3.org/TR/2003/REC-PNG-20031110 o Portable Network Graphics (PNG) Specification, Third Edition. W3C Proposed Recommendation 15 May 2025. https://www.w3.org/TR/2025/PR-png-3-20250515 (AUTHORS) OptiPNG Cosmin Truta . Nelson A. de Oliveira Debian . Cosmin Truta OptiPNG . optipng 7.9.1 2025-05-20 OPTIPNG(1)