Script Library: 1238 scripts
 

jpg-analyse.r

REBOL [ Title: "JPG analyse" Date: 4-Jan-2002/18:22:48+1:00 Version: 1.0.0 File: %jpg-analyse.r Author: "Oldes" Usage: "NEWjpg: jpg-analyse %/e/testjpg.jpg" Purpose: {To remove some data from the JPG files to make them smaller. ^-For example files from Adobe contains so many other informations that the file is twice bigger than may be.} Email: %oliva--david--seznam--cz library: [ level: 'advanced platform: none type: 'tool domain: 'file-handling tested-under: none support: none license: none see-also: none ] ] jpg-analyse: func[ "Analyses the JPG file and tries to remove some unnecessary infos from file" file [file! url! binary!] "JPG file to analyse" /remove tags-to-remove [block!] {If not specified these tags are removed: ["Photoshop 3.0" "ICC_PROFILE" "Adobe" "Ducky"] if presents} /quiet "Will not print informations" /local img to-int buf newimg jfif version units Xdensity Ydensity Xthumbnail Ythumbnail rgb length lng identifier data APP0 ][ if not remove [ tags-to-remove: [ "Photoshop 3.0" "ICC_PROFILE" "Adobe" "Ducky" ] ] img: either binary? file [file][read/binary file] newimg: make binary! length? img to-int: func[i][to-integer to-binary i] msg: func[m][if not quiet [print m]] JFIF: [ ["JFIF^@" copy version 2 skip ( version: (to-int version/1) + ((to-int version/2) / 100) ) copy units 1 skip (units: to-int units) copy Xdensity 2 skip copy Ydensity 2 skip copy Xthumbnail 1 skip copy Ythumbnail 1 skip copy rgb to end ] ( print "JFIF HEADER:" print ["^- version:" version] print ["^- units:" pick [ "no units, X and Y specify the pixel aspect ratio" "X and Y are dots per inch" "X and Y are dots per cm" ] 1 + units ] print ["^- density:" to-pair reduce [to-int Xdensity to-int Ydensity]] print ["^-thumbnail:" to-pair reduce [ to-int Xthumbnail to-int Ythumbnail] ] ) ] parse/all img [ copy buf thru "ÿØ" (insert tail newimg buf) some [ "ÿ" copy APP0 1 skip copy length 2 skip (lng: (to-int length) - 2) copy data lng skip ( identifier: none either APP0 = "à" [ if not quiet [parse/all data JFIF] ][ if not none? data [ parse/all data [ copy identifier to "^@" 1 skip to end ] ] ] either any [ found? find tags-to-remove identifier APP0 = "þ" ;info about the creator's program ][ msg either none? identifier [ ["Removed data:" data] ][ ["Removed tag" mold identifier "lenght:" lng + 4] ] ][ insert tail newimg rejoin ["ÿ" APP0 length data] ] ) ] copy buf to end (insert tail newimg buf) ] msg ["Original image:" length? img "B"] msg ["Optimised image:" length? newimg "B"] newimg ] replace-jpgs: func[ "Replaces all JPG files" /local path tsz1 tsz2 sz1 sz2 ext img newimg modes ][ path: to-file ask {Directory? } if empty? path [path: %./] if (last path) <> #"/" [append path #"/"] if not exists? path [print [path "does not exist"] halt] tsz1: 0 tsz2: 0 foreach file files: read path [ either dir? path/:file [ foreach newfile read path/:file [append files file/:newfile] ][ ext: last (parse mold path/:file ".") if ext = "jpg" [ if error? try [ img: read/binary path/:file modes: get-modes path/:file [modification-date owner-write] if not last modes [ ;change back tail modes true ;set-modes path/:file modes ;uncomment if you want to replace locked files ] sz1: length? img newimg: jpg-analyse/quiet img sz2: length? newimg tsz1: tsz1 + sz1 tsz2: tsz2 + sz2 if sz1 > sz2 [ write/binary path/:file newimg set-modes path/:file modes print [path/:file sz1 sz2] ] ][ print ["ERROR: " path/:file]] ] ] ] print ["Before: " tsz1] print ["Now: " tsz2] print ["Removed:" tsz1 - tsz2] ]
halt ;; to terminate script if DO'ne from webpage
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  • (oliva:david:seznam:cz)