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

[Antoine Monmayrant]

Le Mardi 9 Février 2016 08:34 CET, Philipp Mühlmann <p.muehlmann at gmail.com> a écrit: 
 
> Well, the base function behind "ShowImage" is "Matplot".

I don't get what you mean.
My point is the following: "ShowImage" is not defined in the scilab base install.
You have to install an atom module to get access to it, in this case, it's IPD.
Saddly, IPD is broken for both the fedora and ubuntu linux distributions we use at work so I cannot use it.
IPD fails at detecting the installed opencv library installed.
I tried to patch "IPD.start" to load the installed opencv libs, but it crashes scilab.

Antoine

> 
> 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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> > >
> > >
> > > --
> > > There we have the salad.
> >
> >
> >
> >
> >
> >
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> 
> 
> 
> -- 
> There we have the salad.