distance-btwn-points-D8

start_row = 1478;
end_row = 2246;
meters_per_pixel = 1;
rows = [start_row meters_per_pixel end_row];
start_col = 349;
end_col = 1117;
cols = [start_col meters_per_pixel end_col];
img  = imread('boston.tif','PixelRegion',{rows,cols});
figure; 
hImg = imshow(img);
title('1 meter per pixel');
 
% Specify initial position of distance tool on Harvard Bridge.
hline = imdistline(gca,[271 471],[108 650]);
api = iptgetapi(hline);
api.setLabelTextFormatter('%02.0f meters');
 
% Repeat process but work with a 2 meter per pixel sampled image. Verify
% that the same distance is obtained.
meters_per_pixel = 2;
rows = [start_row meters_per_pixel end_row];
cols = [start_col meters_per_pixel end_col];
img  = imread('boston.tif','PixelRegion',{rows,cols});
figure;    
hImg = imshow(img);
title('2 meters per pixel');    
     
% Convert XData and YData to meters using conversion factor.
XDataInMeters = get(hImg,'XData')*meters_per_pixel; 
YDataInMeters = get(hImg,'YData')*meters_per_pixel;
     
% Set XData and YData of image to reflect desired units.    
set(hImg,'XData',XDataInMeters,'YData',YDataInMeters);    
set(gca,'XLim',XDataInMeters,'YLim',YDataInMeters);
     
% Specify initial position of distance tool on Harvard Bridge.
hline = imdistline(gca,[271 471],[108 650]);
api = iptgetapi(hline);
api.setLabelTextFormatter('%02.0f meters');