white images when using h5read, is it normal ?

Hello,

I have created a hdf5 files with 2 datasets of images to put them as an input in a convolutional neural network.

Before being written in the .h5 files my images are normal but after I created my .h5 file and try to read the data the images are all white.

Here is my code :

h5create('uNetDataSet.h5','/image',size_data_train);
h5create('uNetDataSet.h5','/anno',size_data_train_anno);

h5write('uNetDataSet.h5','/image',Data_train);
h5write('uNetDataSet.h5','/anno',Data_train_anno);

h5disp('uNetDataSet.h5')
Image = h5read('uNetDataSet.h5','/image');
imshow(Image(:,:,:,3));

Is it normal ? What exactly does the function h5write ? If it is not normal, does anyone have a idea how to solve this ?

(I am using Matlab R2015a on Ubuntu 14.04)

Answer 1

[Walter Roberson]

imshow(uint8(Image(:,:,:,3)));

Answer 2

[Image Analyst]

It's possibly a floating point image, so use [] in imshow to automatically scale your image. The problem without doing that is then imshow() will assume your floating point variable is in the range 0-1. If it's not, like it's in the range 0-255 or 0-65535 or some other range, then anything greater than 1 will show up as white.

imshow(Image(:,:,:,3), []);

I'd also recommend not using Image as the name of a variable since there is a built in function called image(). Granted, MATLAB is case sensitive, but it's still preferred to not use the same name even if there is a capitalization difference. Call it myImage or something.