files = dir('*.JPG');
for k = 1:numel(files)
rgb = imread(files(k).name);
rgb = rgb(1:1800, 520:2000, :);
rgb = imresize(rgb, 0.2, 'bicubic');
imwrite(rgb, ['cropped\' files(k).name]);
end
Using this code, I am able to crop simple 8-bit image in bulk but it is not successful with 16 bit signed data.
What is the format of the 16bit signed data ?
the crop of the image and the resize of images should work on the 16bit images.
and How do you imwrite your images ?
Hi Zhang
Thanks for replying.
I am a newbie in coding, so there might be a silly mistake. Images are in tiff format. when applying above code on 16 bit data it shows:
"Warning: Unexpected results may occur with signed pixel data.
> In imwrite at 443
In BulkSubset at 9"
resulting image are blank and got converted into Byte data type from Integer, while same operation on 8-bit unsigned data does not produce any error except data type conversion from integer to byte.
Dear Gopal.
Please tell us why are you using jpg images in your study.
jpg image use to lost the spectral information of any sensor. In remote sensing and image processing it is not a good practice use such kind of images in any study.
Dear Asato
I am not using jpg images that was just to check whether code is working fine or not, that's my mistake that i am showing .jpg in my code . instead of that i am using tiff images, in fact i am working with MODIS EVI product.
Hi,
I'm not sure if this is matlab (haven't worked with it in quite a while) but since it's tagged with programming in matlab maybe this will come as usefull information.
Matlab, as many other high level languages, tends to automatically make the necessary conversions and apparently it handles 8 bit and 16 bit as default (particularly for images, for the rest is double 64).
That said in this link you have many examples for conversions (see subtitle RBG images): http://www.mathworks.com/help/matlab/creating_plots/working-with-8-bit-and-16-bit-images.html
One important point, however, is that if you originally have 8 bit information and convert it to 16 bit information you won't get the precision of a16 bit image, just the 8 bit information with 16 bit precision. So you can convert it but that doesn't mean you would get the same result as the original 16 bit image.
Hope it helps.
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