imxprofile

Name

imxprofile — Draws intensity profiles of an already displayed image

Calling Sequence

[x,y,hprofile,vprofile]=imxprofile(matrix[,option,xscale,yscale,zscale,maximal_luminance])

Parameters

matrix

is an image. It can be either a gray level or an indexed image.

If a color image is displayed, it's internally converted to a gray one to display intensity profiles.

This image should be displayed before invoquing imxprofile.

option

0 to draw the profiles on the image, 1 to draw the profiles in separated windows, 2 to draw the profiles on the image and the gaussian interpolation (used with laser beam images).

Default=0.

xscale, yscale

A multiplication factor on one of the axis. It allows to display coordinates directly in mm (after a calibration to determine the conversion pixels - mm).

Default=1.

zscale

A multiplication factor on the z axis. It can be used to display gray levels in the 0-255 range instead of in the 0-1 range (for example).

Default=1.

maximal_luminance

is useful to choose the scale at which hprofile and vprofile will be displayed.

The default setting is to calculate a value such that the maximal value of the image will be displayed at a quarter of the image.

x, y

are the corresponding column and row in the image matrix.

hprofile, vprofile

Matrix containing the horizontal (or vertical) profile selected.

Description

This is an improved version of improfile: it's supposed to be more intuitive and pleasant.

The function draws the values of pixels on a line and a row. It can draw profiles on the image and in separate windows.

People interested in determining the radius w of a laser beam (in order to calculate its beam waist for example) can try option=2.

Examples

   a=gray_imread(SIPDIR+'images/tru.jpg');
   imshow(a); 
   imxprofile(a);

   //profiles in separate windows
   xbasc();
   imshow(a); 
   imxprofile(a,1)

   //laser beam visualisation
   b=imread(SIPDIR+'images/photonics/laser1.jpg');
   xbasc();imshow(b,[]);
   imxprofile(b,2);

Authors

Jocelyn DRUEL <jocelyn DOT druel1 AT libertysurf DOT fr>

Ricardo Fabbri <ricardofabbri AT users DOTsf DOT net>

Availability

The latest version of the Scilab Image Processing toolbox can be found at

http://siptoolbox.sourceforge.net