USAGE: trim2rect [-f fuzzval] [-c coords] [-b bgcolor] [-p progress] [-g graphic] [-d dcolor] infile outfile
USAGE: trim2rect [-h or -help]

-f ... fuzzval .... fuzz value for determining border color; expressed as (float)
................... percent 0 to 100; default=0 (uniform color)
-c ... coords ..... pixel coordinate to extract color; may be expressed as a
................... gravity value (NorthWest, etc) or as "x,y" value; default
................... is NorthWest=(0,0)
-b ... bgcolor .... background color surrounding region of interest; any valid IM
................... color is allowed; default is to use coords to get color; bgcolor
................... takes precedence over coordinates
-p ... progress ... show progress; choices are: yes or no
-g ... graphic .... draw crop box on input image; yes or no; default=no; graphic
................... image will be the input image name with _cropbox.jpg appended
-d ... dcolor ..... crop box draw color; any valid opaque IM color is allowed:
................... default=red

PURPOSE: Automatically trims the sides of an image until no outer row or column contains the background color.

DESCRIPTION: TRIM2RECT automatically trims the sides of an image one row or column at a time until no side row or column contains the background color. The background color is first floodfilled to be transparent and a -trim is performed to remove excess background color that is completely along any side. Then the alpha channel is extracted. Each side row or column of the alpha channel is then tested for its mean value. If the mean value is less than one, a counter is incremented for that side. Once a side row or column of the alpha channel has a mean of 1, that side row or column is no longer tested. Processing continues until all side rows and columns have a mean value of 1. A crop box is then computed from the counters indicating how many rows and columns should be removed from each side. Finally the image is cropped.

ARGUMENTS:

-f fuzzval ... FUZZVAL is the fuzz amount specified as a percent 0 to 100 (without the % sign). The default=5. A value of zero indicates that border is a uniform color. Larger values are needed when the border is not a uniform color.

-c coords ... COORDS is any location within the border area for the algorithm to find the base border color. It may be specified in terms of gravity parameters (NorthWest, North, NorthEast, East, SouthEast, South, SouthWest or West) or as a pixel coordinate "x,y". The default is the upper left corner = NorthWest = "0,0".

-bg color ... BGCOLOR is the background color surrounding the region of interest. Any valid IM color is allowed. The default is to use coords to get color. The bgcolor takes precedence over coordinates.

-p progress... show PROGRESS in cycles. The choices are: yes (y) or no (n). Each cycle corresponds to a test of all four sides in the order of top, left, bottom, right.

-g graphic ... GRAPHIC specifies to draw the crop box on input image after the initial -trim to remove excess border. Choices are: yes (y) or no (n). The default=no. The graphic image will be the input image name with _cropbox.jpg appended.

-d dcolor ... DCOLOR is the crop box draw color. Any valid opaque IM color is allowed. The default=red.

Note, this script may be quite slow as it processes one row or column at a time.

CAVEAT: No guarantee that this script will work on all platforms, nor that trapping of inconsistent parameters is complete and foolproof. Use At Your Own Risk.