Loading MatLab .fig file as an Image

Good day,

I have recently cropped an image and saved is at a .fig MatLab file so that I can plot out and edit its histogram in the future. Currently I am unsure of how to load the image such that I can do my histogram.

I read online about hgload, but when I load it and plot, it only shows 1 point in the histogram.

Can anyone guide me?

Regards Guan Zhao

Answer 1

[Image Analyst]

That's inefficient and confusing. Just take the histogram again when you want it later, or if you want to save the histogram itself, just save the histogram with save(). Don't save a displayed figure, with all its background, axes tick marks, etc. and then try to get back to the original image from a figure - it just doesn't make sense.

% Save the cropped image
imwrite( croppedImageArray, fullFileName);
% or save the histogram
[pixelCounts grayLevels] = imhist(croppedImageArray);
save(fullMATFileName, 'pixelCounts', 'grayLevels');

[Guan Zhao]

I am figuring out how to save the cropped image so that I will be able to work with it again in the future.

I tried saving with your recommendation using 'imwrite' as shown below

imwrite(I2, 'C:\Users\Desktop\MatLab\Test.JPG', jpg);

The code did not proceed to the next line, so I presume it got stuck at this line. Any idea what is wrong with this line?

[Image Analyst]

Is I2 a uint8 color or grayscale image? What does

>> whos I2

report back? I2 is not single or double is it? Also, the third argument jpg is not needed - it will determine the image file format from the extension of the filename you passed it.

[Guan Zhao]

I2 is an uint8 grayscale image. I am trying to determine the pixel intensity for starters on my cloud project, if you still remember you answered my previous post too.

Anyway on a sidenote, is it possible to show the no. of samples in an image histogram? (The no. of data values used to plot the histogram)

[Image Analyst]

I don't know why your imwrite call didn't work then. It should work.

I gave you code for the histogram. You can examine the output arguments in the debugger's variable editor. Or try

bar(grayLevels, pixelCounts);

[Guan Zhao]

Alright I got it! Thanks!