MATLAB: Tiff format convert using imwrite

tiff

Hi all, I have two files in tiff format. One of them is just a black and white text,and the other one is a colorful image. the black and white can be converted only to a tiff format file using imwrite code whereas the latter can also be converted to a jpg format file using imwrite(the same code) can someone explain the difference between these two tiff files and why the latter one is also convertable to a jpg format?

Best Answer

The black and white one probably reads in as a logical array. imwrite() can write logical arrays to TIFF but not to JPEG. To write a logical array to JPEG use

ArrayGray = uint8(LogicalArray) .* uint8(255);

and then imwrite ArrayGray.

Note, though, that this would produce a grayscale JPEG image, which is fairly rare (I have only ever seen one that was not just a demonstration that creating them was possible.) Some systems might refuse to recognize grayscale JPEG images. You might need to do the conversion to Gray as I indicated and then use

ArrayRGB = ArrayGray(:,:,[1 1 1]);

and then imwrite ArrayRGB

Related Solutions

MATLAB: Black and white image

Try this

[counts, grayLevels] = imhist(grayImage, 256);
if sum(counts(2:end-1)) > 0
  % It's not pure black and white
end
% Get map of non-0 and non-255 pixels
grayPixels = grayImage > 0 & grayImage < 255;
% Get pure black and white image
bw = grayImage; % Initialize

bw(grayPixels) = 0; % Zero out any gray pixels.
% Get gray pixels only
grayOnly = grayImage; % Initialize
grayOnly(~grayPixels) = 0; % Zero out any pure 0 or pure 255 pixels.

MATLAB: White 256×256 image gives me 256x256x3

Try this:

whiteImage = 255 * ones(256, 256, 'uint8');
imwrite(whiteImage, 'White Image.png'); % Save to disk.

Best Answer

Related Solutions

MATLAB: Black and white image

MATLAB: White 256×256 image gives me 256x256x3

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