How to create RGB image with 3 bands from hyperspectral image?

Hi, I have a Hyperion EO-1 satellite image and i want to create an RGB band with band numbers (40,31,13) as (R,G,B). The hyperion image has 242 bands. But I'm having trouble opening the L1R file properly.

I am using Matlab 2011, and 2014 hyperion image. I load the image with hdfinfo and hdfread commands like this;

hdfinfo('EO1H1930282003203110PY.L1R');
fileinfo = hdfinfo('EO1H1930282003203110PY.L1R');
sds_info = fileinfo.SDS(1);
hdfread(sds_info);
ans=imhdf;

But this loads a matrix [3128,242,256] , although it should be [3128,256,242] how can i fix this?

After loading the image as 3D matrix i try to create the RGB image with selecte 3 bands as shown below it creates [3128,3,256] matrix but I cant use imwrite, imshow or any other displaying functions on it.

imrgb [:,1,:] = imhdf [:,40,:];
imrgb [:,2,:] = imhdf [:,31,:];
imrgb [:,3,:] = imhdf [:,13,:];

image(imrgb);
Error using image
Error using image
Indexed CData must be size [MxN], TrueColor CData must be
size [MxNx3]

Please answer, thank you.

[kirti khemka]

i m using the same code for my image error occured ??? Error using ==> permute Out of memory. Type HELP MEMORY for your options.

Error in ==> hdfsdsread at 53 data = permute(data,ndims(data):-1:1);

Error in ==> hdfread at 234 varargout{1} = hdfsdsread(hinfo,start,stride,edge);

Answer 1

[Cong Huynh]

You could use the Scyllarus hyperspectral image processing toolbox. The MATLAB version of this toolbox is available for non-commercial use and can be downloaded from http://scyllarus.research.nicta.com.au/

To load and save multispectral images (consisting of pairs of .hdr and .fla files), the functions to look at are FLARead and FLAWrite under src/io. With these functions you can read from and write to the .fla format (ENVI-compatible), rather than any colour image format. Alternatively you can save the image to a .mat file but this option usually produces a much larger image.

To convert a hyperspectral image to RGB, you could use the function recover_RGBImage.m under /src/shared. There are examples in that .m file.

[Adnan Farooq Awan]

I have an hyperspectral data taken from Brimrose VA210 sensor. I have 61 bands. Can I use this toolbox for that?

Answer 2

[Ben Worker]

Here is a sample code to try. It allowed me to view LR1 images.

field_info=hdfinfo(FILE_NAME);
sds_info = field_info.SDS(1);
imhdf=hdfread(sds_info);
imrgb(:,:,1) = imhdf(:,27,:);
imrgb(:,:,2) = imhdf(:,18,:);
imrgb(:,:,3) = imhdf(:,9,:);
imrgb = double(imrgb);
gain = 3000;
imshow(imrgb/gain)

[Adnan Farooq Awan]

How you found the value of gain?

Answer 3

[Image Analyst]

See this paper, which goes into great detail on the hyperspectral to RGB conversion process: http://my.ece.msstate.edu/faculty/du/JSTARS-VIS.pdf

Answer 4

[Subhadeep Koley]

You can use the hypercube(__) function to read Hyperion EO-1 L1R files and also the colorize(__) method will help you to estimate color image of the Hyperion EO-1 L1R image.

% Read the L1R image (specify your L1R file name here)
hCube = hypercube('EO1H1930282003203110PY.L1R');

% Estimate the RGB image
rgbImg = colorize(hCube, 'method', 'rgb', 'ContrastStretching', true);

% Visualize the RGB image
figure
imshow(rgbImg)
title('RGB image')

NOTE: The above mentioned fetures come under Image Processing Toolbox's Hyperspectral Imaging Library support package, and can be downloaded from here. For more information on Hyperspectral Imaging Library see the documentation.