How to extract curve data from such a JPEG image?

When I use a machine to record the ECG data, it can only save as .jpg format, just like the figure I show in the below.

But I want to extract the green line digital data. The problem is that the three green lines data are continues, I wonder if I can use some methods to extract green line data and combine them together?

Answer 1

[darova]

Try this simple script. Like it please

We have a picture with green pixels. What we gonna do now?

[Yihan Ma]

Thanks for your code!

It could keep green lines with white background.

But I need to combine these three green lines together to extract the whole signal data, cause these lines are continues signals.

To guarantee without amplitude and time disorder, I think I need to know the start matrix position of these figures, like I show in the below. May be to know the position of red point and the height of the first green line frame.

Or do you know any method that could extract the green lines datas, and combine these together without distortion?

[darova]

What about paint (standard mirosoft application)?

[Rik]

Can't you convert the lines to pixel height? Then you can use the value of the last point from the first line as the offset for the second line.

[Yihan Ma]

Got it, I can use 'impixelinfo' to chck the position of the pixels, thx!