<html> <head> <title>Gri: `mask' command</title> </head> <body bgcolor="#FFFFFF" text="#000000" link="#0000EE" vlink="#551A8B" alink="FF0000"> <!-- newfile Mask.html "Gri: `mask' command" "Gri Commands" --> <!-- @node Mask, New, Ls, List Of Gri Commands --> <a name="Mask" ></a> <img src="./resources/top_banner.gif" usemap="#navigate_top" border="0"> <table summary="top banner" border="0" cellspacing="0" cellpadding="0"> <tr> <td width="150" valign="top"> <font size=-1> <br> Chapters: </br> <a href="Introduction.html">1: Introduction</a><br> <a href="SimpleExample.html">2: Simple example</a><br> <a href="InvokingGri.html">3: Invocation</a><br> <a href="GettingMoreControl.html">4: Finer Control</a><br> <a href="X-Y.html">5: X-Y Plots</a><br> <a href="ContourPlots.html">6: Contour Plots</a><br> <a href="Images.html">7: Image Plots</a><br> <a href="Examples.html">8: Examples</a><br> <a href="Commands.html">9: Gri Commands</a><br> <a href="Programming.html">10: Programming</a><br> <a href="Environment.html">11: Environment</a><br> <a href="Emacs.html">12: Emacs Mode</a><br> <a href="History.html">13: History</a><br> <a href="Installation.html">14: Installation</a><br> <a href="Bugs.html">15: Gri Bugs</a><br> <a href="TestSuite.html">16: Test Suite</a><br> <a href="Acknowledgments.html">17: Acknowledgments</a><br> <a href="License.html">18: License</a><br> <br> Indices:</br> <a href="ConceptIndex.html"><i>Concepts</i></a><br> <a href="CommandIndex.html"><i>Commands</i></a><br> <a href="BuiltinIndex.html"><i>Variables</i></a><br> </font> <td width="500" valign="top"> <map name="navigate_top"> <area alt="index.html#Top" shape="rect" coords="5,2,218,24" href="index.html#Top"> <area alt="ListOfGriCommands.html#ListOfGriCommands" shape="rect" coords="516,2,532,24" href="ListOfGriCommands.html#ListOfGriCommands"> <area alt="Gri: `ls' command" shape="rect" coords="557,2,573,24" href="Ls.html"> <area alt="Gri: `new' command" shape="rect" coords="581,2,599,24" href="New.html"> </map> <map name="navigate_bottom"> <area alt="index.html#Top" shape="rect" coords="5,2,218,24" href="index.html#Top"> <area alt="Gri: `new' command" shape="rect" coords="581,2,599,24" href="New.html"></map> <h3>9.3.23: `<font color="#82140F"><code>mask</code></font>'</h3> <!-- latex: \index{mask} --> <TABLE SUMMARY="Example" BORDER="0" BGCOLOR="#efefef" WIDTH="100%"> <TR> <TD> <PRE> <font color="#82140F"> `mask the image [to {uservalue .u.}|{imagevalue .i.}]' </font></PRE> </TD> </TR> </TABLE> <p> Examine both the image and the mask pixel by pixel. For any pixels which have a mask value of 1 (which indicates an invalid region of the image), change the image value. If no `<font color="#82140F"><code>to</code></font>' phrase is present, change the image value to 0 in pixel units. If the `<font color="#82140F"><code>to uservalue .u.</code></font>' phrase is present, change the pixel to hold the imagevalue that corresponds to this uservalue (see `<font color="#82140F"><code>set image range</code></font>' command for a discussion of this correspondance). If the `<font color="#82140F"><code>to imagevalue .i.</code></font>' phrase is present, change the pixel to hold that imagevalue (in range 0 to 255 inclusive for 8-bit images). <p> </table> <img src="./resources/bottom_banner.gif" usemap="#navigate_bottom" border="0"> </body> </html>