why i cannot display an image

I have done wavedec2 on an image and extracted the approximate coefficients using appcoef2.I want to display the approximate image but its showing total white.why is it so. how to get the image?

1 Comment

Dishant Arora
Dishant Arora on 21 Feb 2014
Edited: Dishant Arora on 21 Feb 2014
show us your code, it would be easier to find where you went wrong.

Sign in to comment.

 Accepted Answer

Walter Roberson
Walter Roberson on 21 Feb 2014
use imagesc() or use imshow() with [] as the second parameter.

3 Comments

The reason "why" is because it's probably a floating point image, and if so, imshow() expects all floating point images to be inthe range 0-1. If it's more than 1, it will get clipped to 1 and show up as all white (255 on your display). Using [] will scale your image to 0-1, which is the range it wants, and then display it. If you use imagesc() it picks some funky default colormap (not grayscale like it should default to) that you will probably want to change if you use that.
imagesc() picks up the current colormap, whatever that happens to be.
it helped..thnx

Sign in to comment.

More Answers (1)

john
john on 24 May 2019
please solve this issue , i have try hundred of times
command line error is
Attempt to execute SCRIPT image as a function:
C:\Users\ejaz\Desktop\working space\image.m
Error in images.internal.basicImageDisplay (line 24)
hh = image(cdata, ...
Error in imshow (line 293)
hh = images.internal.basicImageDisplay(fig_handle,ax_handle,...

Categories

Tags

Asked:

on 21 Feb 2014

Answered:

on 24 May 2019

Community Treasure Hunt

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

Start Hunting!