On Aug 30, 2013, at 5:30 PM, HoweLab wrote:
> Hi All.
>
> I am trying to change all of the colors in an RGB image to specific
> grayscale values (there are 256 distinct RGB combinations in my image and I
> know how I want/need each of them to be 'assigned' to a grayscale
> intensity). I seem to be stuck, however, in that I cannot seem to get the
> 'changeValues' command to accept a variable with a hex value - i.e. if
> 'color' is a variable with a hex value, the command 'changeValues(0x0000ff,
> 0x0000ff, color) doesn't change anything.
Use
color = red<<16 + green<<8 + blue;
to merge red, green and blue values to create an RGB variable.
newImage("blank", "RGB White", 200, 200, 1);
rvalue=10;
gvalue=255;
bvalue=10;
color = rvalue<<16 + gvalue<<8 + bvalue;
wait(1000);
changeValues(0xffffff,0xffffff,0xff0000)
wait(1000);
changeValues(0xff0000,0xff0000,color);
-wayne
> Here is a sample macro that
> demonstrates the problem:
>
> newImage("blank", "RGB White", 200, 200, 1);
> rvalue=10;
> gvalue=255;
> bvalue=10;
> rhex=toHex(rvalue);
> ghex=toHex(gvalue);
> bhex= toHex(bvalue);
> color = "0x" + rhex + ghex + bhex;
> print(color);
> selectImage("blank");
> wait(500);
> changeValues(0xffffff,0xffffff,0xff0000)
> wait(500);
> changeValues(0xff0000,0xff0000,color);
>
> Even though the value of 'color' that is returned/printed looks correct, the
> box does not change to the correct color for that value. I found a macro -
> RGBtoHEX - that I thought might help; it utilized a syntax I'm not familiar
> with (~e.g. 'color = "0x" + pad(rhex) + "" + pad(ghex) + "" + pad(bhex)';
> I've never seen the 'pad' command before in this context).
>
> The reason I want to use a variable is because I simply didn't want to write
> 256 separate statements to get the job done and wanted to use a series of
> 'for' loops.
>
> Any insights are greatly appreciated.
>
> -Alan H.
>
> --
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http://imagej.1557.x6.nabble.com/Use-of-variables-with-hex-value-for-changeValues-function-tp5004617.html> Sent from the ImageJ mailing list archive at Nabble.com.
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