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| author | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2009-03-11 21:11:55 +0000 |
|---|---|---|
| committer | giraffedata <giraffedata@9d0c8265-081b-0410-96cb-a4ca84ce46f8> | 2009-03-11 21:11:55 +0000 |
| commit | 7d84c5e8a7f663eefb75bcc9c2608289b523eba9 (patch) | |
| tree | de2fb3ad6c942f6da3c7bab613cc91c26d42d54b /pnmcrop.html | |
| parent | f1d8b86c5a5d640bcf9a8859bd37312565db395c (diff) | |
| download | netpbm-mirror-7d84c5e8a7f663eefb75bcc9c2608289b523eba9.tar.gz netpbm-mirror-7d84c5e8a7f663eefb75bcc9c2608289b523eba9.tar.xz netpbm-mirror-7d84c5e8a7f663eefb75bcc9c2608289b523eba9.zip | |
"miscellaneous update"
git-svn-id: http://svn.code.sf.net/p/netpbm/code/userguide@850 9d0c8265-081b-0410-96cb-a4ca84ce46f8
Diffstat (limited to 'pnmcrop.html')
| -rw-r--r-- | pnmcrop.html | 49 |
1 files changed, 28 insertions, 21 deletions
diff --git a/pnmcrop.html b/pnmcrop.html index 2d1542d5..87c010fb 100644 --- a/pnmcrop.html +++ b/pnmcrop.html @@ -2,7 +2,7 @@ <HTML><HEAD><TITLE>Pnmcrop User Manual</TITLE></HEAD> <BODY> <H1>pnmcrop</H1> -Updated: 30 November 2006 +Updated: 11 March 2009 <BR> <A HREF="#index">Table Of Contents</A> @@ -131,29 +131,36 @@ if necessary. <dt><b>-borderfile=</b><i>filename</i> <dd>Use the image in the file named <i>filename</i> instead of the input -image to determine where the borders of the input image are. - -<p>Without this option, <b>pnmcrop</b> examines the input image and -figures out what part of the image is border and what part is -foreground (not border). With this option, <b>pnmcrop</b> finds the -borders in one image, then uses the those four border sizes (left, -right, top, bottom) in cropping a different image. - -<p>The point of this is that you may want to help <b>pnmcrop</b> to -come to a different conclusion as to where the border are by -preprocessing the input image. For example, consider an image that -has speckles of noise in its borders. <b>pnmcrop</b> isn't smart -enough to recognize these as noise; it sees them as foreground image. -So <b>pnmcrop</b> considers most of your borders to be foreground and -does not crop them off as you want. To fix this, run the image -through a despeckler such as <b>pbmclean</b> and tell <b>pnmcrop</b> -to use the despeckled version of the image as the <b>-borderfile</b> -image, but the original speckled version as the input image. That -way, you crop the borders, but retain the true foreground image, -speckles and all. +image to determine where the borders of the input image are and the +background color. + +<p>Without this option, <b>pnmcrop</b> examines the input image and figures +out what part of the image is border and what part is foreground (not border), +as well as the background color. With this option, <b>pnmcrop</b> finds the +borders in one image, then uses the those four border sizes (left, right, top, +bottom) in cropping a different image. Furthermore, if you use +<b>-margin</b> to add borders, the color of those borders is the background +color <b>pnmcrop</b> detects in the border file. + +<p>The point of this is that you may want to help <b>pnmcrop</b> to come to a +different conclusion as to where the borders are and what the background color +is by preprocessing the input image. For example, consider an image that has +speckles of noise in its borders. <b>pnmcrop</b> isn't smart enough to +recognize these as noise; it sees them as foreground image. So <b>pnmcrop</b> +considers most of your borders to be foreground and does not crop them off as +you want. To fix this, run the image through a despeckler such as +<b>pbmclean</b> and tell <b>pnmcrop</b> to use the despeckled version of the +image as the <b>-borderfile</b> image, but the original speckled version as +the input image. That way, you crop the borders, but retain the true +foreground image, speckles and all. <p>This option was new in Netpbm 10.29 (August 2005). +<p>Before Netpbm 10.46 (March 2009), the original image and not the +border file determines the background color. <b>pnmcrop</b> +fails if there is no apparent background color in the original image +(i.e. the corners of the image don't have a common color). + <DT><B>-verbose</B> <DD>Print on Standard Error information about the processing, |