C#: Detecting All Shades Of Violet [closed]

asked 2018-06-09 08:47:43 -0500

G'day, I'm trying to detect if an image has any shades of Violet in it.

I made this in C# however, after some research, I came across this library and was wondering if it could help to improve what I already have?

I did see that it can detect a Red stop sign, but what about all the different shades of red?

private bool Process(Image image)
        using (Bitmap bitmap = new Bitmap(image))
            int infected = 0;
            int total = 0;

            LockBitmap lockBitmap = new LockBitmap(bitmap);

            for (int x = 0; x != lockBitmap.Width; x++)
                for (int y = 0; y != lockBitmap.Height; y++)
                    if (lockBitmap.GetPixel(x, y).GetHue() + 25 > Color.FromKnownColor(KnownColor.Violet).GetHue() + 20) //need to fine tune.



            if (infected > 450) //need to fine tune.
                return true;
                MessageBox.Show("Not Damaged");
                return false;

Here are some of the images I'm working with.
Image0 <-- This image as far as I can tell detects the violet colour(s)
Image1 <-- This one does too
This one does too, which seems pretty weird because unless my eyes need checking, I cant see any violet.
This one doesn't detect any violet.

What can I do to make sure that it only detects violet (any shade of violet) that we humans can see?
Thanks in advanced.

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Closed for the following reason question is off-topic or not relevant by berak
close date 2018-06-09 08:51:47.138319


sorry, but we cannot help you with it, since it is not related to opencv at all.

berak gravatar imageberak ( 2018-06-09 08:51:26 -0500 )edit

actually, abi, I was looking for a method that OpenCV might have and or if it was capable of doing so

Andrew Eberle gravatar imageAndrew Eberle ( 2018-06-09 08:53:37 -0500 )edit

there is no support for c#, either.

but usually, you'd filter a hsv range using inRange()

berak gravatar imageberak ( 2018-06-09 08:57:03 -0500 )edit