How to print a matrix as an uncompressed image file.

2 次查看（过去 30 天）
Corrado
Corrado 2011-5-13
I have a matrix M (600x600) and I make a color plot with
imagesc(M)
set(gca,'YDir','normal')
axis equal
axis off
The problem is that I need to export what I get but exactly what I get and only that. I want an image (tiff or something else that is not compressed) of 600x600 pixels, each one of the color I have get by imagesc(M).
Ideally, if I go to the information of my output file I'll can read 600x600pixels 24bit RGB.
Or if I have a 1200x1200 with 600dpi resolution (2inch by 2 inch image) I need to export that exactly and only that..
I tried with print -r600 -zbuffer -dtiffn (with -loose or -noui too) but I always save back ground too.
In my mind my wish is to obtain, for a plot 300x300, a file .tiff (...or .eps or anything else that may be open with different pc with different installed programs..) maybe of 720KB...but the most important request is that if i want it with 100dpi, the file produced is 3inch x 3inch and with exactly 90000 points.

请先登录，再回答此问题。

回答（4 个）

Doug Hull
Doug Hull 2011-5-16
Have you tried IMWRITE?
Walter Roberson
Walter Roberson 2011-5-16
Note the reference to imagesc() and note that a third dimension is not specified for the matrix. Your data is being scaled and translated by imagesc() with the current color map being used. imwrite() would not do that scaling and translation for you.
[Code amended Nov 30 2011, per Matt's remarks]
OutputResolution = 100;
Mmin = min(M(:));
Mmax = max(M(:));
C = colormap();
numcol = size(C,1);
if Mmin == Mmax
Mscaled = repmat(reshape(C(end,:),1,1,3),size(M,1),size(M,2),1);
else
Mscaled = ind2rgb(round((M - Mmin) ./ (Mmax - Mmin) * (numcol-1)), C);
end
imwrite(Mscaled, FILENAME, 'tiff', 'Compression', 'none', 'Resolution', OutputResolution);
  2 个评论
Matt Fig
Matt Fig 2011-5-19
Walter, if I understand correctly you have misused the COLORMAP function by indexing with end. Unless things have changed since 2007b, it would be better to define a variable at the beginning of your code:
C = colormap;
Then index into and reference C in the rest of the code.

请先登录，再进行评论。

Corrado
Corrado 2011-5-23
Tank you very much. I delete the "if" part of the code because it makes me some problem and I'll never have Mmin==Mmax! All the rest of the code works very well!! tank you so much!!
Oliver Woodford
Oliver Woodford 2011-6-17
The function sc was written to solve exactly this problem.

类别

在 Help Center 和 File Exchange 中查找有关 Orange 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by