Messages from Usenet group comp.lang.idl-pvwave, compiled by Paulo Penteado
Re: how to highlight some pixels in the image
Or maybe I can implement it in ENVI? "Xiaoying Jin" <xje4e@mizzou.edu> wrote in message news:abct59$dl$1@dipsy.missouri.edu... > Hi, there, > > I want to do the following operations in IDL: > I display a gray level image, select a pixel in the image, the location and > the gray level of the pixel will be displayed. > Then all the pixels having the same gray level in the image will be > highlighted. > > How can I program to implement it? Actually, I am a newer for this kind of > operations. So any suggestion will be appreciated. > > Best regards, > > Xiaoying Jin > >
Xiaoying Jin (xje4e@mizzou.edu) writes: > I want to do the following operations in IDL: > I display a gray level image, select a pixel in the image, the location and > the gray level of the pixel will be displayed. > Then all the pixels having the same gray level in the image will be > highlighted. > > How can I program to implement it? Actually, I am a newer for this kind of > operations. So any suggestion will be appreciated. You make a copy of your image, scaled so that you can set one pixel to another color: display = BytScl(image, Top=!D.Table_Size-2) You load a color: TVLCT, 255, 255, 0, =!D.Table_Size-1 You set all the pixels at your value equal to the color: I = Where(image EQ value, count) IF count GT 0 THEN display[I] = !D.Table_Size-1 You display the fixed up image: TV, display I hacked up a little program I have lying around here to show you how it is done. It is called Light_Pixel and you can find it here: http://www.dfanning.com/misc/light_pixel.pro Start it like this: IDL> Light_Pixel You can pass it your image as an argument, if you like. When you click your cursor in the image, it will display the location of the cursor, the value of the image at that location, and will temporarily (for two seconds) light up all pixels in the image that have that value with a yellow color. Cheers, David -- David W. Fanning, Ph.D. Fanning Software Consulting Phone: 970-221-0438, E-mail: david@dfanning.com Coyote's Guide to IDL Programming: http://www.dfanning.com/ Toll-Free IDL Book Orders: 1-888-461-0155
David Fanning (david@dfanning.com) writes: > You load a color: > > TVLCT, 255, 255, 0, =!D.Table_Size-1 Whoops! Coyote is lurking again... TVLCT, 255, 255, 0, !D.Table_Size-1 Cheers, David -- David W. Fanning, Ph.D. Fanning Software Consulting Phone: 970-221-0438, E-mail: david@dfanning.com Coyote's Guide to IDL Programming: http://www.dfanning.com/ Toll-Free IDL Book Orders: 1-888-461-0155
Thanks for helping me out. Coyote is really an expert at this. Reading a good program is an enjoy for me. Best regards, Xiaoying Jin "David Fanning" <david@dfanning.com> wrote in message news:MPG.1743afe22249759f9898c3@news.frii.com... > David Fanning (david@dfanning.com) writes: > >> You load a color: >> >> TVLCT, 255, 255, 0, =!D.Table_Size-1 > > Whoops! Coyote is lurking again... > > TVLCT, 255, 255, 0, !D.Table_Size-1 > > Cheers, > > David > -- > David W. Fanning, Ph.D. > Fanning Software Consulting > Phone: 970-221-0438, E-mail: david@dfanning.com > Coyote's Guide to IDL Programming: http://www.dfanning.com/ > Toll-Free IDL Book Orders: 1-888-461-0155