masking geotiff Landsat data using shapefile

I have Landsat Image and shape file , I want to masking this data using a shape file but getting error because my (data model type projected not geographic) So the mask hallways contain zeros... I will write my code and Images of references.

File_Name = 'LC08_L1TP_01_T1_B4.TIF';
[I,R1]=geotiffread(File_Name);
R2 = geotiffinfo(File_Name);
[x,y] = pixcenters(R2);
[X,Y] = meshgrid(x,y);
roi = shaperead('shapefile.shp');
rx = roi.X(1:end-1);
ry = roi.Y(1:end-1);
mask = inpolygon(X,Y,rx,ry); 
I2 = bsxfun(@times, I, cast(mask,class(I)));

[KSSV]

What error you get? We cannot try your code without the inputs..

[chant of rain]

 the mask array hallways contain zero values.

Answer 1

[Junxue Zhang]

I think your input tif file and shapefile do not share the same map projection, so that their boundary boxes do not match. First you should reproject your shapefile to the new map projection that your raster uses. And then you codes will take effect. Also, you can't ignore the last values in roi.X and roi.Y, because these values make polygon closed.

BTW, if your shapefile contains multiple polygons, I recommend you to do a for loop for the variable roi, like:

mask = zeros(5000,5000,'logical');
for i = 1:length(roi)
    rx = roi(i).X;
    ry = roi(i).Y;
    mask_temp = inpolygon(X,Y,rx,ry);
    mask = mask | mask_temp;
end

[Emanuele Ferrentino]

Hi,

thank you very much Junxue Zhang for your code.

In this way I can generate a binary image from a shapefile with the same projection of my geotiff.

I need to do another step. I'm looking for a way to associate a value (damage_idx) on the binary image previously obtained. I have the following shapefile:

roi = 
  64×1 struct array with fields:
    Geometry
    BoundingBox
    X
    Y
    DN
    Prov
    Com
    Localita
    Lat1
    Lon1
    damage_idx

Anyone knows how to do?