> Could you please show me how to read in a colored bitmap image
> then convert it to 8-bit gray scale bitmap image in LV?
>
You don't mention what version of LV you are using, but for years
now there have been icons available that will read BMPs and a few
other file formats. Once you have the data in, you can display it
in either an intensity graph or in a picture control. Displaying
a color image as gray scale requires a little bit of computation.
If the image is indexed, has a color table, then only the color
table needs to be changed. If its a true color image, then each
pixel value needs to be changed. What you want to do is take each
color, and compute a gray scale value for it. The simplest is to
average the Red, Green, and Blue values in the color
so that they
map to a gray value between 0 for black to 255 for white. Because
the human eye is more influenced by green, it tends to look better
if you don't average them evenly, but rather scale it so that green
is 40%, red is 35%, and blue is 25%.
Averaging the color usually means taking an int32 and splitting it
into four bytes using either the Split functions that are located
in advanced I think, or using some division or shifting and Int/
Remainder division.
This really isn't that complicated once you get into it. Another
option is to look on the info-labview archives to see if someone
has already submitted a VI to do this. Also, the IMAQ vision
add-on most likely has VIs for this and much much more.
Greg McKaskle
