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January 2008
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2008.01.25 09:25 "Re: Tiffcrop and tiff2pdf", by Beppe Costagliola
Hi Richard, thanks for your suggestions. I've tried in both ways. -m 1200,100,1804,876 gives a cropped image (no problem in calculating the -m values at runtime, because we already do this) -m 1200,100 -X 1500 -Y 500 produces a distorted image with a size double of the original ! I will keep on trying the first option. At present we use Imagemagick (convert -crop) but because it runs on a iSeries platform the command is executed via a rs/6000 interpreter. While I can run tifflib with their tools (including tiffcrop) in C native mode. Note that we have to run this command more than 150,000 times per day and the performance is a real issue. PS. Do you know of a barcode reader available in open source ? Thanks. Giuseppe. . --- Richard Nolde <nrichard8@qwest.net> ha scritto: > 1. Re: TIffcrop might be called tiffextract (Andy > Cave) > >> Please, note that tiffcrop is a part of libtiff > for quite a some time > >> (and it is part of stable branch of libtiff) and > probably already is > >> being used in scripts or called from programs, so > it is not harmless to > >> change its name. But everything is possible with > a good reason, of > >> course. > >> > >> Best regards, > >> Andrey > > Andrey's point is well taken. I originally > proposed that the code that > > is now tiffcrop should replace tiffcp since it is > a superset of the > > tiffcp utiltity, but Frank Warmerdam rightly noted > that tiffcp was far > > to important to take a change on breaking and > certainly no > > functionality should be removed. I started > exploring with a simple > > crop option and it grew from there. I will try to > check out the CVS > > version soon as I think there may be half a dozen > more options that I > > have added since the 3.8.2 release. A quick check > of my source shows > > options for breaking pages into X columns by Y > rows, or various Page > > sizes, eg Letter, Legal, etc (which are useful for > document processing > > but not meaningful for abstract images unless you > just happen to want > > to print a huge image on sheets of a given size), > output orientations > > of portrait, landscape, auto, ouput margins added > to pages rather than > > subtracted from the original, and the ability to > specify new X and Y > > resolution tags. These were not in the original > release so I will have > > to see if they made it into CVS before the 3.9.0 > branch. One warning > > to users of the old version. In order to > accomodate the new flags, > > the case of the old flags has changed in some > cases so you will want > > to check your scripts for compatability before > upgrading. > > Anyone is free to provide a symlink with a more > appropriate name for > > their particular installation. Tiffcrop it shall > remain. > > > > 3. How to clip an image with Tiffcrop (beppe > costagliola) > > > > > ---------------------------------------------------------------------- > > There are actually two ways to do this. First you > must specify your > > units as pixels with the -U px option. Second > specify your reference > > edge for the measurements -E top. Third, specify > the margins you want > > to subtract (clip/crop/remove) from the original > that will not be > > copied to the new image. The margins MUST be > specified in the > > following order and separate only by commas, top, > left, bottom, right. > > -m 1200,100,1804,876. This should leave an opening > 1500 x 500 between > > the margins but the right and bottom margins are > rather a pain to > > compute and will cause problems if your images > vary in size. You can > > use the flags for a fixed size region, -X 1500 -Y > 500 with only the > > first two margins and tiffcrop will compute the > proper region and > > ignore anything to the right and below the > selected region if you only > > need to select a single region from each image. > Note that This would > > give you a command line something like this: > tiffcrop -E top -U px -m 1200,100 -X 1500 -Y 500 > source.tif destination.tif > > Note: Units must come first to override the values > found in the tiff > file. Margins are calculated in the current units, > eg actually pixels > for px, or inches, or centimeters but the later two > require that the > file have a valid resolution for both dimensions. > The units in which you > specify the margins or any dimensions for X and Y, > are independent of > the units that might be stored (or defaulted) in the > file. Tiffcrop > converts between the internal units specified in the > file to the type of > units you specify on the command line before it > calculates which pixels > to select. Any margins not specified are assumed to > be zero. > > If you want to select more than one region within > the cropped borders, > you can use the -Z option and the regions will be > computed AFTER the > margins are subtracted. > > Richard Nolde > > > > > > ------------------------------ > > > > Message: 3 > > Date: Thu, 24 Jan 2008 17:09:23 +0100 (CET) > > From: beppe costagliola <beppecosta@yahoo.it> > > Subject: [Tiff] How to clip an image with Tiffcrop > > To: tiff@lists.maptools.org > > Message-ID: > <218112.46229.qm@web26205.mail.ukl.yahoo.com> > > Content-Type: text/plain; charset=iso-8859-1 > > > > Tiffcrop seems to work fine but I don't understand > the > > parameters that should be passed to. > > > > For example: > > > > I have an image with ImageWidth = 2476 and > ImageLength > > = 3504 > > > > I would like to extract an area that is at X = 100 > and > > > > Y = 1200 giving an image of Width = 1500 and > Lenght = > > 500. > > > > Thanks. > > > _______________________________________________ > Tiff mailing list: Tiff@lists.maptools.org > http://lists.maptools.org/mailman/listinfo/tiff > http://www.remotesensing.org/libtiff/ > ___________________________________ L'email della prossima generazione? 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