Thread Subject: Axes control in GUI

Hi,

I have a toy example of a video player implemented in a GUI.
It works fine, but for some reason, the second frame is
shown in a new figure (then the playback happens in the
original axes). What am I doing wrong?

Code extracts are below. Thanks in advance,
Gheorghe

Here is the initialization code (in _OpeningFcn....):

%%
handles.vr = varargin{1};
handles.timer = timer('Period',0.5, ...
    'ExecutionMode', 'fixedSpacing', ...
    'timerFcn', {@fcnOnTimer, handles.vr, handles.axes1 } );
handles.state = 0; % i.e. stopped
guidata(hObject, handles);

here is the result of pressing the Play button:

%%
handles.state = 1 - handles.state;
if handles.state,
    start(handles.timer);
else
    stop(handles.timer);
end
guidata(hObject,handles);

and finally here is the callback function:

function varargout = fcnOnTimer(obj,event, vr, cax)
imshow(getnext(vr), 'Parent', cax)

Instead of using imshow function to display each frame,
updating 'CData' property of image obj in the current axes
is the better and faster way, and it maybe resolve your
problem.

function varargout = fcnOnTimer(obj,event, vr, cax)
imobj = findobj('parent',cax,'type','image');
set(imobj,'Cdata',getnext(vr));
%%imshow(getnext(vr), 'Parent', cax)

And you could change 'cax' to 'imobj' in the inputs of
fcnOnTimer function

function varargout = fcnOnTimer(obj,event, vr, imobj)
set(imobj,'Cdata',getnext(vr));

Anh Huy Phan
RIKEN - BSI


"Gheorghe " <gheorghe.postelnicu@gmail.com> wrote in
message <flkodl$fkb$1@fred.mathworks.com>...
> Hi,
>
> I have a toy example of a video player implemented in a
GUI.
> It works fine, but for some reason, the second frame is
> shown in a new figure (then the playback happens in the
> original axes). What am I doing wrong?
>
> Code extracts are below. Thanks in advance,
> Gheorghe
>
> Here is the initialization code (in _OpeningFcn....):
>
> %%
> handles.vr = varargin{1};
> handles.timer = timer('Period',0.5, ...
> 'ExecutionMode', 'fixedSpacing', ...
> 'timerFcn', {@fcnOnTimer, handles.vr, handles.axes1
 } );
> handles.state = 0; % i.e. stopped
> guidata(hObject, handles);
>
> here is the result of pressing the Play button:
>
> %%
> handles.state = 1 - handles.state;
> if handles.state,
> start(handles.timer);
> else
> stop(handles.timer);
> end
> guidata(hObject,handles);
>
> and finally here is the callback function:
>
> function varargout = fcnOnTimer(obj,event, vr, cax)
> imshow(getnext(vr), 'Parent', cax)

Hi Huy,

Thanks for the reply! I think your suggestion makes a lot of
sense and after implementing it, the new figure doesn't pop
up anymore. However, the image doesn't refresh anymore -
although I added a refreshdata especially trying to tackle
this (please see below code). Any suggestions?

function varargout = fcnOnTimer(obj,event, vr, cax)
imobj = findobj('parent',cax, 'type', 'image');
set(imobj, 'Cdata', getnext(vr))
refreshdata(imobj)
%imshow(getnext(vr), 'Parent', cax)

"Huy " <phananhhuy@mathworks.com> wrote in message
<flkqlr$s2o$1@fred.mathworks.com>...
> Instead of using imshow function to display each frame,
> updating 'CData' property of image obj in the current axes
> is the better and faster way, and it maybe resolve your
> problem.
>
> function varargout = fcnOnTimer(obj,event, vr, cax)
> imobj = findobj('parent',cax,'type','image');
> set(imobj,'Cdata',getnext(vr));
> %%imshow(getnext(vr), 'Parent', cax)
>
> And you could change 'cax' to 'imobj' in the inputs of
> fcnOnTimer function
>
> function varargout = fcnOnTimer(obj,event, vr, imobj)
> set(imobj,'Cdata',getnext(vr));
>
> Anh Huy Phan
> RIKEN - BSI
>
>
> "Gheorghe " <gheorghe.postelnicu@gmail.com> wrote in
> message <flkodl$fkb$1@fred.mathworks.com>...
> > Hi,
> >
> > I have a toy example of a video player implemented in a
> GUI.
> > It works fine, but for some reason, the second frame is
> > shown in a new figure (then the playback happens in the
> > original axes). What am I doing wrong?
> >
> > Code extracts are below. Thanks in advance,
> > Gheorghe
> >
> > Here is the initialization code (in _OpeningFcn....):
> >
> > %%
> > handles.vr = varargin{1};
> > handles.timer = timer('Period',0.5, ...
> > 'ExecutionMode', 'fixedSpacing', ...
> > 'timerFcn', {@fcnOnTimer, handles.vr, handles.axes1
> } );
> > handles.state = 0; % i.e. stopped
> > guidata(hObject, handles);
> >
> > here is the result of pressing the Play button:
> >
> > %%
> > handles.state = 1 - handles.state;
> > if handles.state,
> > start(handles.timer);
> > else
> > stop(handles.timer);
> > end
> > guidata(hObject,handles);
> >
> > and finally here is the callback function:
> >
> > function varargout = fcnOnTimer(obj,event, vr, cax)
> > imshow(getnext(vr), 'Parent', cax)
>

Hi Gheorghe,

I'm sorry not to clarify in detail. To use this way, you
need to display the first frame in the axes. If not, this
object imobj is empty.

imobj = findobj('parent',cax, 'type', 'image');

Here is an example which displays the image sequences
'AT3_1m4_01.tif' 'AT3_1m4_02.tif' 'AT3_1m4_03.tif'
(existing in the folder: MATLAB\toolbox\images\imdemos)

im1 = imread('AT3_1m4_01.tif');
imobj = imshow(im1);
pause(1)

im2 = imread('AT3_1m4_02.tif');
set(imobj,'Cdata',im2)
pause(1)

im3 = imread('AT3_1m4_03.tif');
set(imobj,'Cdata',im3)

Return to your function, it could be modified as below

function varargout = fcnOnTimer(obj,event, vr, cax)
imobj = findobj('parent',cax, 'type', 'image');
if ~isempty(imobj)
    set(imobj, 'Cdata', getnext(vr))
else
    axes(cax)
    imshow(getnext(vr))
end


Anh Huy Phan
RIKEN - BSI


"Gheorghe " <gheorghe.postelnicu@gmail.com> wrote in message
<flkson$58j$1@fred.mathworks.com>...
> Hi Huy,
>
> Thanks for the reply! I think your suggestion makes a lot
of
> sense and after implementing it, the new figure doesn't pop
> up anymore. However, the image doesn't refresh anymore -
> although I added a refreshdata especially trying to tackle
> this (please see below code). Any suggestions?
>
> function varargout = fcnOnTimer(obj,event, vr, cax)
> imobj = findobj('parent',cax, 'type', 'image');
> set(imobj, 'Cdata', getnext(vr))
> refreshdata(imobj)
> %imshow(getnext(vr), 'Parent', cax)
>
> "Huy " <phananhhuy@mathworks.com> wrote in message
> <flkqlr$s2o$1@fred.mathworks.com>...
> > Instead of using imshow function to display each frame,
> > updating 'CData' property of image obj in the current
axes
> > is the better and faster way, and it maybe resolve your
> > problem.
> >
> > function varargout = fcnOnTimer(obj,event, vr, cax)
> > imobj = findobj('parent',cax,'type','image');
> > set(imobj,'Cdata',getnext(vr));
> > %%imshow(getnext(vr), 'Parent', cax)
> >
> > And you could change 'cax' to 'imobj' in the inputs of
> > fcnOnTimer function
> >
> > function varargout = fcnOnTimer(obj,event, vr, imobj)
> > set(imobj,'Cdata',getnext(vr));
> >
> > Anh Huy Phan
> > RIKEN - BSI
> >
> >
> > "Gheorghe " <gheorghe.postelnicu@gmail.com> wrote in
> > message <flkodl$fkb$1@fred.mathworks.com>...
> > > Hi,
> > >
> > > I have a toy example of a video player implemented in
a
> > GUI.
> > > It works fine, but for some reason, the second frame is
> > > shown in a new figure (then the playback happens in the
> > > original axes). What am I doing wrong?
> > >
> > > Code extracts are below. Thanks in advance,
> > > Gheorghe
> > >
> > > Here is the initialization code (in _OpeningFcn....):
> > >
> > > %%
> > > handles.vr = varargin{1};
> > > handles.timer = timer('Period',0.5, ...
> > > 'ExecutionMode', 'fixedSpacing', ...
> > > 'timerFcn', {@fcnOnTimer, handles.vr, handles.axes1
> > } );
> > > handles.state = 0; % i.e. stopped
> > > guidata(hObject, handles);
> > >
> > > here is the result of pressing the Play button:
> > >
> > > %%
> > > handles.state = 1 - handles.state;
> > > if handles.state,
> > > start(handles.timer);
> > > else
> > > stop(handles.timer);
> > > end
> > > guidata(hObject,handles);
> > >
> > > and finally here is the callback function:
> > >
> > > function varargout = fcnOnTimer(obj,event, vr, cax)
> > > imshow(getnext(vr), 'Parent', cax)
> >
>

thanks that worked great here is the code i used to test it
incase someone wants to do the same

    pic=rand(480,640);
    
    imobj = findobj(handles.axes1, 'type', 'image');
    if ~isempty(imobj)
    set(imobj, 'Cdata', pic)
    else
    axes(handles.axes1)
    imagesc(pic)
    end