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diff --git a/ds9/doc/ref/contour.html b/ds9/doc/ref/contour.html new file mode 100644 index 0000000..25dc20d --- /dev/null +++ b/ds9/doc/ref/contour.html @@ -0,0 +1,189 @@ +<!DOCTYPE doctype PUBLIC "-//w3c//dtd html 4.0 transitional//en"> +<html> + <head> + <meta http-equiv="Content-Type" content="text/html; + charset=windows-1252"> + <meta name="GENERATOR" content="Mozilla/4.78 [en] (X11; U; Linux + 2.4.7-10 i686) [Netscape]"> + <title>Contours</title> + </head> + <body link="#0000ee" alink="#ff0000" bgcolor="#ffffff" text="#000000" + vlink="#551a8b"> + <h3><img alt="" src="../sun.gif" height="98" align="middle" + width="100"> Contours</h3> + <blockquote> + <p>DS9 can create and display contours as an overlay on an image. + The Analysis Contours menu is used to display contours. To + create, copy, paste, and configure contours, use the + Analysis Contour Parameters menu.</p> + <p><b>Contour Parameters </b></p> + <p>When creating a new contour, a dialog box appears, in which the + user selects the number of contour levels, smoothness, and the + distribution of the contours. </p> + <p><b> Contour Levels</b></p> + <p>Specifies the number of contour levels to be generated. A + typical number is between 1 and 10. Note: large numbers of + contours can take a long time to generate. </p> + <p><b> Contour Smoothness</b></p> + <p>Specifies how smooth the contours are. A smoothness level of 1 + will evaluate the contour at each image pixel. A level of 2 will + evaluate the contour at every other pixel. The larger the + number, the quicker the contour will be generated, and the less + detail will be available. </p> + <p><b> Contour Scale</b></p> + <p>Specifies the distribution of the contour levels. <br> + </p> + <p><b> Contour Method</b></p> + <p>There are two methods that are available to calculate the + contour lines. The first, BLOCK, blocks down the image, by the + smoothness factor, before contours are calculated. As a result, + the larger the smoothness, the faster the result. The second + method, SMOOTH, smooths the image before calculating contours. + As a result, the larger the smoothness, the slower the result.<br> + </p> + <p><b> <a name="ContourFiles"></a>Contour Files</b></p> + <p>A contour file is an ASCII file containing a header, global + properties, coordinate system, contour levels, and contour + points. <br> + </p> + <blockquote> + <p><b> Header</b></p> + <p>A DS9 contour file may start with the following optional + header: </p> + <blockquote> <tt># Contour file format: DS9 version 7.5<br> + </tt></blockquote> + <p><b> Global Properties</b></p> + <p>Global properties affect all contour levels unless a line + level attribute is specified. The <tt>global</tt> keyword is + first, followed by a list of keyword = value pairs. Multiple + global property lines may be used within a region file. </p> + <blockquote> <tt>global color=green width=1 dash=1 dashlist=8 3<br> + </tt></blockquote> + <p><b> Coordinate Systems</b></p> + <p>For each contour file, it is important to specify the + coordinate system used to interpret the contour points, i.e., + to set the context in which the positions are interpreted. For + this purpose, the following keywords are recognized: </p> + <blockquote> <tt>PHYSICAL + +# + + + + + + + + + pixel coords of original file using LTM/LTV</tt> <br> + <tt>IMAGE + +# + + + + + + + + + pixel coords of current file</tt> <br> + <tt><tt><tt>FK4,B1950 + + # sky coordinate systems</tt> <br> + FK5,J2000 +# + + + + + + + + + sky coordinate systems</tt> <br> + </tt><tt><tt><tt>ICRS + +# + sky coordinate systems</tt> <br> + </tt>GALACTIC + +# + + + + + + + + + sky coordinate systems</tt> <br> + <tt>ECLIPTIC + +# + + + + + + + + + sky coordinate systems</tt> <br> + <tt>WCS + + # primary WCS<br> + </tt><tt>WCSA + # + secondary WCS<br> + </tt><tt>LINEAR + +# + + + + + + + + + linear primary WCS</tt> <tt><br> + </tt></blockquote> + </blockquote> + <blockquote> + <p><b> Contour Level</b></p> + <p>Each contour level is composed of a line value, line + attributes and one or more contours. Line attributes are + specified at the start of a new level and only affect contours + within that level . </p> + <blockquote> <tt>level=15.78775 color=pink width=2 dash=yes dashlist=2 + 2<br> + </tt></blockquote> + <p><b> Contour</b></p> + <p>Each contour is composed of one or more X,Y coordinates, with + a deliminator of space or comma, starting with "(" and + ending with ")". Contours are not closed.<br> + </p> + </blockquote> + <blockquote> + <blockquote><tt>(</tt><tt>202.4836468 47.22380226</tt><tt><br> + </tt><tt> 202.4833538 47.2239185</tt><tt><br> + </tt><tt> 202.4831634 47.22409874</tt><tt><br> + </tt><tt> 202.4829883 47.22428858</tt><tt>)</tt><br> + </blockquote> + </blockquote> + <blockquote> + <p><br> + </p> + <blockquote> </blockquote> + </blockquote> + <p><br> + </p> + <blockquote> + <blockquote> </blockquote> + <blockquote> </blockquote> + <blockquote> </blockquote> + </blockquote> + </blockquote> + </body> +</html> |