Dear guys
I want to extract blue spots from saturation image in Opencv ..I have no idea about what is the threshold value for getting blue from saturation..
Regards,
Palanikasi
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PalaniKasi
- Posts: 52
- Joined: Mon Dec 14, 2015 1:51 pm
Re: How to get blue images from saturation image using openc
I assume you have converted to HSV or HSI colour space.
The colour (e.g. blue rather than yellow, red etc) is in the Hue component.
Saturation encodes how strongly coloured a pixel is, not what colour it is.
For low values of intensity saturation values are undefined (noise).
For low values of saturation Hue is undefined (noise). You may need to Threshold first for I>I_min then S>S_min then for H_low<H>H_hi.
You could examine pixel values in each component for pixels of your target colour.
You could code adjustable thresholds and vary the values until you get a suitable result.
The colour (e.g. blue rather than yellow, red etc) is in the Hue component.
Saturation encodes how strongly coloured a pixel is, not what colour it is.
For low values of intensity saturation values are undefined (noise).
For low values of saturation Hue is undefined (noise). You may need to Threshold first for I>I_min then S>S_min then for H_low<H>H_hi.
You could examine pixel values in each component for pixels of your target colour.
You could code adjustable thresholds and vary the values until you get a suitable result.
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PalaniKasi
- Posts: 52
- Joined: Mon Dec 14, 2015 1:51 pm
Re: How to get blue images from saturation image using openc
I have attached the image where i should count the blue ones
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- udm1.jpg (17.66 KiB) Viewed 686 times
Re: How to get blue images from saturation image using openc
What have you tried so far?