can image tiff convert to grayscale

as title

i have pictue which file is tiff but it is flase coding about convert (Image file cannot be uploaded)

i read the image and "gray_image = rgb2gray(image)"

but it is error what i should do

thanks Ur reading and answering

Answer 1

[Walter Roberson]

zipname = 'https://www.mathworks.com/matlabcentral/answers/uploaded_files/1674421/sample.zip';
tfile = fullfile(tempdir(), 'sample.zip');
filestr = urlwrite(zipname, tfile);
filenames = unzip(filestr);

imgname = filenames{1};

info = imfinfo(imgname)

info = struct with fields:
                     Filename: '/users/mss.system.p5sjk/eot i.tiff'
                  FileModDate: '20-Apr-2024 11:03:54'
                     FileSize: 191826
                       Format: 'tif'
                FormatVersion: []
                        Width: 652
                       Height: 97
                     BitDepth: 32
                    ColorType: 'truecolor'
              FormatSignature: [73 73 42 0]
                    ByteOrder: 'little-endian'
               NewSubFileType: 0
                BitsPerSample: [8 8 8 8]
                  Compression: 'LZW'
    PhotometricInterpretation: 'RGB'
                 StripOffsets: [8 7551 15132 22767 30420 38017 45641 53249 60998 68674 76415 84188 92015 100004 107793 115624 123518 131472 139588 147599 155729 ... ] (1x25 double)
              SamplesPerPixel: 4
                 RowsPerStrip: 4
              StripByteCounts: [7543 7581 7635 7653 7597 7624 7608 7749 7676 7741 7773 7827 7989 7789 7831 7894 7954 8116 8011 8130 8226 8304 8437 8541 2166]
                  XResolution: 96
                  YResolution: 96
               ResolutionUnit: 'Inch'
                     Colormap: []
          PlanarConfiguration: 'Chunky'
                    TileWidth: []
                   TileLength: []
                  TileOffsets: []
               TileByteCounts: []
                  Orientation: 1
                    FillOrder: 1
             GrayResponseUnit: 0.0100
               MaxSampleValue: [255 255 255 255]
               MinSampleValue: [0 0 0 0]
                 Thresholding: 1
                       Offset: 191404
                    Predictor: 'Horizontal differencing'
                 ExtraSamples: 2

%ExtraSamples of 2 indicates Unassociated Alpha Values

img = imread(imgname);
rgb = img(:,:,1:3) .* img(:,:,4);    %take into account the alpha
gray_image = rgb2gray(rgb);

imshow(rgb); title('rgb')

imshow(gray_image); title('gray')

Answer 2

[Image Analyst]

image is a built-in function. Do not use it as the name of your variable. Zip up your image and attach the zip file with the paperclip icon.

[bozheng]

Thanks for the help