Re: RGB to 32 Bit Gray

Hi Wayne,

I got the latest beta version and your macro works fine.

However, even with the revised version, the lookup table seems to be
inverted. For densitometry applications I would like black to stick out
as a mountain in a surface plot and white to become the lowlands. How
can I make sure black is **always** a high point in a surface plot when
using this conversion macro?

Thanks heaps! ImageJ is a great software!
Art

Wayne Rasband wrote:
>> I tried your Macro (IJ 1.35g, Windows XP). It worked however the
>> resulting 32 bit gray image turned out to be inverted,a matter of byte
>> order??
> 
> 
> The newImage() function was creating an image with an inverting lookup
> table. Adding 'black' (fill with black) to the second argument fixes the
> problem. Here is the updated macro.
> 
>    if (bitDepth!=24)
>        exit("RGB image required");
>    setBatchMode(true);
>    w = getWidth;
>    h = getHeight;
>    rgb = getImageID;
>    newImage("32-bit", "32-bit black", w, h, 1);
>    float = getImageID;
>    for (y=0; y<h; y++) {
>        showProgress(y, h);
>        for (x=0; x<w; x++) {
>            selectImage(rgb);
>            v = getPixel(x,y)&0xffffff;
>            selectImage(float);
>            setPixel(x, y, v);
>        }
>    }
>    resetMinAndMax;
>    setBatchMode(false);
>    //run("16-bit");
> 
> -wayne

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