Fwd: Editing the FFT of a jpeg

Posted by Joel Sheffield on Sep 21, 2009; 9:25pm
URL: http://imagej.273.s1.nabble.com/Editing-the-FFT-of-a-jpeg-tp3691067p3691070.html

Sorry if this came through in an odd format before. mailer problems --Joel

---------- Forwarded message ----------
From: Joel Sheffield <[hidden email]>
Date: Mon, Sep 21, 2009 at 3:20 PM
Subject: Re: Editing the FFT of a jpeg
To: Robby Connor <[hidden email]>


You can tell if the system is reading true black by passing our
coursor over the area and then looking at the menu bar.  You will see
the xy coordinates of the cursor, and the value of the pixel at that
location.  I wonder if when you switch to 32 bit, your black is not
truly 0.000000.

Joel

> So I tried filling with cntrl+f instead of deleting and managed to
> instantly
> get it to work on both of my computers.  Then, on one of my
> computers I
> tried to screw around a bit and changed the type of the picture from
> 8-bit
> to 32-bit, and it stopped working.  It didn't work when I switched
> it back
> to 8-bit either.  Black is 0, not 255, so that doesn't seem to be
> the
> problem.  I'm not sure if checking the color LUT is the only test
> for
> finding if ImageJ is filling with true black.  I don't know why
> ImageJ is
> being so finicky, but I am writing a procedure for other people to
> follow
> using this method, so I need to know as much as I can about this
> process.
> Does anyone have suggestions of what the problem is and how to fix
> it?  Thanks.

--
Joel B. Sheffield, Ph.D.
Biology Department, Temple University
1900 North 12th Street
Philadelphia, PA 19122
[hidden email]
[phone], fax [phone]
http://astro.temple.edu/~jbs <http://astro.temple.edu/%7Ejbs>