Crop out a section of the image in imshow, how?

I have an image I, I want to crop out a section of the image so i dont use the whole image in the analysis.

I have two coordinates at the upper and lower corner, like

pts = [ 234 355; 1678 764];

that is p1 = [ 234; 355] and p2 = [1678; 764]. I want to create a rectangle within the area of these coordinates. The total image size is [1936, 1216].

My issue is that I get a little confused with the image coordinates, since the upper left corner has coordinate [1,1], lower left is [0,1216], upper right is [1936,1] and lower right is [1936,1216],.. (not like with a figure). I am not getting the coordinates correctly.

so how do I have to write to get the second rectangular cropped image in the right area?

I2 = I ( some coordinates) .. for example I2 = I(p1(1):p2(1), p1(2):p1(2)). this is the wrong area though

I been at this for an hour and I cant see how to make it work... :( please help!!

Answer 1

[KSSV]

Read about imcrop. Let I be your image.

rect = [234 355 (1678-234) (764-355)]
iwant = imcrop(I,rect)
imshow(iwant)

[Happy PhD]

Thanks, I think i solved it.

I2=I(p1(2):p2(2), p1(1):p2(1)); 

I will look into your version.

[KSSV]

Yes, you can do this too.