Since we are at it

[andu]

A little something to share: this is a script which reads the width and height in a given JPEG file. I was planing to enable some weblog cgi scripts I made to handle photos and set the width and height parameters in html so that the images even if they are slightly bigger they will fit into a given rectangle and be scaled proportionally. True scaling of images usually requires extra software present on a server.
Put this in a button:

on mouseUp
answer file ""
put url ("binfile:" & it) into rawFile
put length(rawFile) into tLen
put offset(numtochar("255")&numtochar("217"), rawFile) into eoj
if eoj+2>=tLen then put 0 into tCount
else put eoj into tCount
repeat while tCount<tLen
put offset(numtochar("255"), rawFile,tCount) into tOff
put chartonum(char tCount+tOff+1 of rawFile) into tChar
if tChar is among the items of "192,193,194,195" then
put char (tCount+tOff+5) to (tCount+tOff+8) of rawFile into rawSize
put baseconvert(chartonum(char 1 of rawSize),10,16)\ &baseconvert(chartonum(char 2 of rawSize),10,16) into hSize
put baseconvert(chartonum(char 3 of rawSize),10,16)\ &baseconvert(chartonum(char 4 of rawSize),10,16) into wSize
put "H="&baseconvert(hSize,16,10) & space &\ "W="&baseconvert(wSize,16,10) into dimensions
exit repeat
end if
add tOff to tCount
end repeat
put dimensions
end mouseUp

I'm sure it can be optimized but my knowledge of binary data is less then minimal. One thing the script doesn't check is if the file is a true JPEG.
A similar process can read/extract the thumbnail image if the JPEG has one and/or the exif data if it exists but I have a family to feed and my time for playing is over;-).


Regards, Andu Novac
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