MATLAB Central Newsreader - image in axes: making grid visible

image in axes: making grid visible

runcyclexcski@yahoo.com — Wed, 22 Aug 2007 00:36:02 -0400

I display an image in an axes, and I want the grid in the axes and the
tickmarks pointing inwards being visible, i.e. being on top of the
image. But the image always covers up the grid and the tickmarks. Is
there any way to avoid that? I found a workaround by displaying the
tickmarks outward, but with the grid there is no workaround. I looked
in this group and in help and did not find anything. Matlab 6p5, about
to upgrade to R2007.

Re: image in axes: making grid visible

Gautam Vallabha — Wed, 22 Aug 2007 16:29:50 -0400

In article <1187742962.261037.112010@m37g2000prh.googlegroups.com>,
runcyclexcski@yahoo.com says...
> I display an image in an axes, and I want the grid in the axes and the
> tickmarks pointing inwards being visible, i.e. being on top of the
> image. But the image always covers up the grid and the tickmarks. Is
> there any way to avoid that? I found a workaround by displaying the
> tickmarks outward, but with the grid there is no workaround. I looked
> in this group and in help and did not find anything. Matlab 6p5, about
> to upgrade to R2007.

You can try changing the color of the grid and the axis.

----------
load clown.mat
figure;
image(X); colormap(map)

set(gca,'tickdir','in')
set(gca,'xcolor','w', 'ycolor', 'w');
% another way to set the color
set(gca,'xcolor', [1 1 0], ...
'ycolor', [1 1 0]);
----------

--
Gautam

Re: image in axes: making grid visible

runcyclexcski@yahoo.com — Wed, 22 Aug 2007 19:30:35 -0400

> You can try changing the color of the grid and the axis.
>
> ----------
> load clown.mat
> figure;
> image(X); colormap(map)
>
> set(gca,'tickdir','in')
> set(gca,'xcolor','w', 'ycolor', 'w');
> % another way to set the color
> set(gca,'xcolor', [1 1 0], ...
> 'ycolor', [1 1 0]);
> ----------

Nope, it did not do anything.

Re: image in axes: making grid visible

runcyclexcski@yahoo.com — Wed, 22 Aug 2007 19:37:35 -0400

... interestingly, it does work with the clown image. But it does not
work with mine.

I load my image like this:

frame_image = image('cdata',myMatrix,'cdatamapping','scaled');

Re: image in axes: making grid visible

Gautam Vallabha — Wed, 22 Aug 2007 20:27:51 -0400

In article <1187811455.531528.178200@j4g2000prf.googlegroups.com>,
runcyclexcski@yahoo.com says...
> ... interestingly, it does work with the clown image. But it does not
> work with mine.
>
> I load my image like this:
>
> frame_image = image('cdata',myMatrix,'cdatamapping','scaled');

Change the 'Layer' property of the axis (This puts the grid
lines on top of the image);
-----------
load clown.mat;
image('cdata', X, 'cdatamapping','scaled');
grid on; axis tight;
set(gca, 'layer', 'top');
set(gca, 'xcolor', 'w', 'ycolor', 'w');
-----------

--
Gautam

Re: image in axes: making grid visible

runcyclexcski@yahoo.com — Sat, 25 Aug 2007 03:22:45 -0400

Hey, Gautam, it worked, thanks a bunch!!

Re: image in axes: making grid visible

meha — Sat, 31 Oct 2009 08:40:08 -0400

> I m converting a jpg image into binary using following code:
g=imread('G.jpg');
save g;
load g;
BW = im2bw(g,map,0.4);
imshow(g,map), figure, imshow(BW)

But in ths code, following error is coming:
??? Undefined function or variable 'map'.

How to remove this error?
>
>

Re: image in axes: making grid visible

Steven Lord — Mon, 02 Nov 2009 00:18:34 -0500

"meha " <sign2speech@gmail.com> wrote in message
news:hcgt58$sn9$1@fred.mathworks.com...
>
>> I m converting a jpg image into binary using following code:
> g=imread('G.jpg');
> save g;
> load g;
> BW = im2bw(g,map,0.4);
> imshow(g,map), figure, imshow(BW)
>
> But in ths code, following error is coming:
> ??? Undefined function or variable 'map'.
>
> How to remove this error?

Create the variable map before attempting to use it.

--
Steve Lord
slord@mathworks.com
comp.soft-sys.matlab (CSSM) FAQ: http://matlabwiki.mathworks.com/MATLAB_FAQ

Re: image in axes: making grid visible

ImageAnalyst — Mon, 02 Nov 2009 03:10:26 -0500

What's the point of saving and then loading it? You already have g so
that is unecessary. Your image didn't have a map, so don't use it
subsequently because it's undefined. Just don't use it. Try this:

clc;
close all;
clear all;
workspace; % Show the Workspace panel.

% Read in standard monochrome MATLAB demo image.
grayImage = imread('coins.png');
% Threshold it
binaryImage = im2bw(grayImage, 0.4);

% Display the original image.
subplot(1,2,1);
imshow(grayImage);
title('Original gray scale image');

% Display the thresholded, binary logical image.
subplot(1,2,2);
imshow(binaryImage, []); % Note use of [] to scale it so you can see
it.
title('Thresholded (binary) image');
set(gcf, 'Position', get(0, 'ScreenSize')); % Maximize figure.

Re: image in axes: making grid visible

Make — Mon, 02 Nov 2009 04:08:01 -0500

runcyclexcski@yahoo.com wrote in message <1187742962.261037.112010@m37g2000prh.googlegroups.com>...
> I display an image in an axes, and I want the grid in the axes and the
> tickmarks pointing inwards being visible, i.e. being on top of the
> image. But the image always covers up the grid and the tickmarks. Is
> there any way to avoid that? I found a workaround by displaying the
> tickmarks outward, but with the grid there is no workaround. I looked
> in this group and in help and did not find anything. Matlab 6p5, about
> to upgrade to R2007.
>
Try like this: if you display an axes in GUI,you can set the property of axes
which called 'visible' 'off'