Detecting thin Red lines in the eye.

Hi forum.
I want to detect thin red lines in the eye that are caused by some drug effect. I just want to take a idea that by how I can do that. the approach I am thinking to use is,

1. Convert Image to Grayscale from RGB (off-course it wont detect the RED lines but it will detect the thin lines).
2. Apply Hough transformation for line fitting and detect all the lines in the image.
3. Apply a suitable threshold to remove the unnecessary lines and keeping the only original ones.
4. Showing the lines on the Original RGB image by just plotting them.

I'm newbie at Image Processing. If anyone have better approach or can improve my current approach, DO SHARE!
I want to use MATLAB R2013 for this as processing tool.
this is the kind of lines im talking about.

Hi,

I´d first select the area of interrest.
(white background, red lines)

Then I´d do a filtering on those red colored lines. (you still have the color information, so use it)
This avoids to recognize lines with other colors.

After that (or during that) you could switch to grayscale.

Klaus

Thankyou for the input, Klaus.
When you say, "filtering on red lines". which type of filtering you are talking about? can you be more specific?
I was also thinking to separate the red lines using the color information but I have mostly dealt the image in grayscale so having very little knowledge of RGB. If you tell me what kind of filtering we can apply to get the red colors separated, please share!
Thanks
Ahsan

Hi,

I was pointing to the "red color" within the whole RGB area, not to the "lines", because your first step is to convert to grey scale, so you loose the "red" color information.

Don´t know much about such random red lines recognition, so I can´t recommend a filter.
(I know a little about using two dimensional FFT for fixed pattern recognition)


Klaus

A graphics program would be great for you to experiment with. It offers a variety of effects that you can use on a photograph. These would help you determine the best way to approach your task. For instance:

* enhance contrast

* locate pixels that are a certain color (or range of color)

* change those pixels to a different color

* analyze color distribution in image and create histogram

* change to greyscale

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I use a program called GraphicConverter on my PowerMac. Its menu does not have a command for detecting lines such as in the eye.

Photoshop is a popular and versatile graphics editor for Windows machines. It costs money.

You may find a free program which has a lesser amount of features.

Finally you may need to write a program which detects the lines in the eye.