Getting BinaryImage write to work

[loafdog]

Hi,

My team has tried using BinaryImage write() but could not get any files to appear in root dir on crio. I was playing with it a bit last night and eventually got images to appear. I have a few questions.
Given something like:
BinaryImage img = image.thresholdRGB(0, 40, 25, 255, 0, 40);

1- img.write("thresh.jpg"); did not work. img.write("/tmp/thresh.jpg"); did not work. img.write("/tmp/thresh.png") works. I did not try other file types. Not sure if writing a .png to / works or not... it was late and I was happy to get something working. Any ideas why using jpg does not work? Any reason writing to / may not work? I don't remember if I tried writing png to /. I am able to ftp the camera test sample jpg images to /. I did not try creating/writing to a text file yet.

2- the png image was either all black or had some red pixels/particles. We are using a green ring light. Our camera, RGB values, and filters need tuning but we should get something other than black/red. I looked in sunspotfrcsdk/lib/WPILibJ/src/edu/wpi/first/wpilibj/image/BinaryImage.java and found:

   public void write(String fileName) throws NIVisionException{
        Pointer colorTable = new Pointer(1024);
        //Black Background
        colorTable.setByte(0, (byte)0);   //B
        colorTable.setByte(1, (byte)0);   //G
        colorTable.setByte(2, (byte)0);   //R
        colorTable.setByte(3, (byte)0);     //Alpha
        //Red Particles:
        colorTable.setByte(4, (byte)0);     //B
        colorTable.setByte(5, (byte)0);     //G
        colorTable.setByte(6, (byte)255);   //R
        colorTable.setByte(7, (byte)0);     //Alpha
        try {
            NIVision.writeFile(image, fileName, colorTable);
        } finally {
            colorTable.free();
        }
    }

I changed two lines to:

        colorTable.setByte(5, (byte)255);     //G
        colorTable.setByte(6, (byte)0);   //R

After that saved images contained green pixels. I could see what thresholdRGB and convexHull and other filters were doing. Is this the right thing to do to get green images to appear? Seems like a hacky kind of way to make it work, but I'll take it for now.

-Maciej