how do i change the dicom file's brightness and contrast with slider bar in app designer

I want to change the brightness and contrast with slider bar.

i made button callback function that read the sagittal direction of 256 dicom files and then print coronal, axial, sagittal mri 2d image through axes,

i do the brightness first, but it didnt work and keep erroring.

here is slider bar's callback function:

function SliderValueChanged(app, event)

% take slider value

sliderValue = app.UIKnob.Value;

% change brightness

brightnessAdjusted = imadjust(app.images, [sliderValue/100, 1], []);

% update sagittal mri image

app.UIAxes_2.Visible = 'off';

img2 = imagesc(squeeze(brightnessAdjusted(:, 128, :)), 'Parent', app.UIAxes_2);

colormap(app.UIAxes_2, 'gray');

title(app.UIAxes_2, 'Sagittal');

axis(app.UIAxes_2, 'image');

% update axial mri image

app.UIAxes_1.Visible = 'off';

img1 = imagesc(squeeze(brightnessAdjusted(128, :, :)), 'Parent', app.UIAxes_1);

colormap(app.UIAxes_1, 'gray');

title(app.UIAxes_1, 'Axial');

axis(app.UIAxes_1, 'image');

% update coronal mri image

app.UIAxes_3.Visible = 'off';

img3 = imagesc(squeeze(brightnessAdjusted(:, :, 128)), 'Parent', app.UIAxes_3);

colormap(app.UIAxes_3, 'gray');

title(app.UIAxes_3, 'Coronal');

axis(app.UIAxes_3, 'image');

end

Answer 1

[Rik]

You should use caxis instead. That way you can adjust brightness and contrast directly without having to redraw the image every time.

If you need inspiration, you can have a look at how I implemented window leveling in this FEX submission. It cannot be directly used in AppDesigner, but seeing the code should help.

[민주 곽]

thanks for answering but i have to use app desginer. and i think caxes is not in app designer.

[Rik]

My bad, I wrote caxes instead of caxis, which has now been renamed to clim.

As long as you specify the parent object, calling clim on a uiaxes object works just fine, so you can in fact use it in AppDesigner.