Can I find a measurement of micrometers in matlab using image processing ?

Hey there,

My task is to calibrate the position of a 2D robot with a micrometer range, using camera and image processing on matlab.What i did so far is that i took an image that contains two dots with a known dimension and I found the ratio between the pixels and the known dimensions. But the problem is that I'm still getting measurements error if other images read on the same script that have the same number of pixels but of different measurements.

The steps that i took: 1) Read the image 2)bilinear and bicubic interpolation of the iamge (

1. Reading the image
2. bilinear interpolation following it with bicubic interpolation "increase the size of the image by 5"
3. filter the image using imfilter(x,h), were h = ones(5,5)/25;
4. sharpen the image using imsharpen(c,'Radius',10,'Amount',20);
5. then filter the image again using imfilter(x,h), were h = ones(10,10)/25;#rgb2gray(I2);%changing from rgb to grey
6. im2bw(b);%changing into matrix
7. detecting the traced point [rows, columns] = find(c== 0);#finding mean of columns and rows mean(C);mean®;
8. and then multiplying by the ratio to get the exact measurement

But im still getting an error between 10 to 50 micrometers dependent on the position of the points on the images.

I will be grateful for your help.

Yours sincerely Amir Emilio !