[Scilab-users] ?==?utf-8?q? Put an image as the background of an axis

[Philipp Mühlmann]

Well, the base function behind "ShowImage" is "Matplot".

You can use a search engine of your choice to find ShowImage.sci.

"ShowColorImage" than is using "ShowImage" to create a colored Image.

Hope that helps,

Philipp




2016-02-09 8:04 GMT+01:00 Antoine Monmayrant <amonmayr at laas.fr>:

>
> Le Mardi 9 Février 2016 00:04 CET, Philipp Mühlmann <p.muehlmann at gmail.com>
> a écrit:
>
> > Well, as I understand you want to plot a function over an background
> image.
> >
> > In the case the image pixel number fits the X-Y range of your graph it's
> > rather simple.
>
> Well, it is, unless IPD does not work on your system, which is my case!
> None, absolutely none of the image processing toolboxes work on my machine.
> And it's not only my machine, it's the case for most of the machines we
> have at work.
> So I cannot rely on an image processing toolbox to achieve what I want and
> I have to rely on base functions.
>
> Thanks anyway for you help,
>
> Antoine
>
> >
> > img = ReadImage(IPD_PATH + 'demos\teaset.png');
> > rows = size(img,'r');cols = size(img,'c');
> > img(rows,1,:) = (0);        // changing left lower image corner for
> > checking purpose
> >                                         // change all 3 colour
> > channels to get a black pixel
> > ShowColorImage(img,'');
> > a = gca();a.axes_visible = ["on","on","off"];x = linspace(1,600,600);y
> > = 1/2*(x);plot(x,y,'-');a.data_bounds = [0,0;cols,rows];
> >
> > Two tricky things though:
> >
> > 1st: image coordinates (center of pixel) start at "1", hence there is a
> gap
> > of 0.5 between image borders and the axes
> >
> > 2nd: it might become tricky if you want to have negative values on the
> axis.
> >
> > Probably there is a way to shift the image to other position within the
> > coordinate system?
> >
> >
> > So....not sure if this helps your purpose.
> >
> > You could also switch "ON" / "OFF" the background image by access the
> > children of the figure, such as:
> >
> > IMGPlot = a.Children(2);   // children(2) is the background in this
> > caseIMGPlot.visible = 'off';
> >
> >
> > A complete other way would be to combine two images of same size.
> > Say...background image is img1.
> >
> > your plot = img2.
> > Plot the graph and save the figure as a temporary image.
> >
> > load img1
> > load temporary image
> >
> > If size (img1) == size(img2)....You could use SIVP module to linear
> combine
> > two images:
> >
> > img_gray = double(RGB2Gray(img));img2 = zeros(rows, cols) +
> > 255;img2(rows/2,:) = 0;img3 = imlincomb( 0.5, img_gray, 0.4, img2)
> > // the values here define some kind of transparency.figure();
> > ShowImage(img3,'');
> >
> >
> >
> > Best regards,
> > Philipp
> >
> >
> >
> >
> > 2016-02-08 17:49 GMT+01:00 Jan Åge Langeland <j-lan at online.no>:
> >
> > >
> > >
> > > On 08.02.2016 11:47, antoine.monmayrant at laas.fr wrote:
> > >
> > > Hi everyone,
> > >
> > > I just failed at placing an image behind a plot.
> > > I thought that would be easy:
> > >     - create a figure
> > >     - create an image uicontrol
> > >     - create an axis
> > >     - plot in the axis
> > >     - set axis.filled="off"
> > >
> > > Apparently I was wrong.
> > > I did not find a way to overlap a plot with transparent background
> over my
> > > image.
> > > It seems that the image is always above the plot no matter what order
> the
> > > uicontrol/axes where created.
> > > I also tried to put both of them inside the same frame, but I did not
> work
> > > either.
> > >
> > > Any idea?
> > >
> > >
> > >
> > > ShowImage(im,'J2');
> > >
> > > b=newaxes();
> > > b.filled = "off";
> > >  plot(a)
> > >
> > > JÅ
> > >
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> > >
> > >
> > >
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> > >
> > >
> >
> >
> > --
> > There we have the salad.
>
>
>
>
>
>
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-- 
There we have the salad.
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