QML won't save camera settings

[Pixtar]

Hi all,

I am using Qt5.2.1 (GCC 4.8, armeabi-v7a) at Windows8.1(x64) and a Samsung Galaxy S4 Mini with Android 4.2.2.

I tried to compile the qml example "qdeclarative-camera" and it worked to start the app with the smartphone and save images.

I tried also to modify the source to test some settings like changing exposuretime, iso, focus, contrast, etc.

Whatever I tried to change - contrast, iso or saturation - nothing happened.

What states or status do the camera should have to save the settings? Does it need to be stopped? Does it need a special captureMode? Are the settings reset by the function searchAndLock? Is it a bug at Qt5.2.1? Is Samsung blocking such functions? Do I need special variables in the pro-file like MOBILITY or TARGET.CAPABILITY?

It's very annoying, that I can't find any hint to solve the problem on my own.

Any hint is appreciated.

Greetings,
Pixtar

[wysota]

What do you mean by "save the settings"? save them where?

[Pixtar]

What do you mean by "save the settings"? save them where?

I mean the simple fact, when I'm using i.e. this little snippet:

camera.imageProcessing.saturation = 1
console.debug( camera.imageProcessing.saturation )

camera.imageProcessing.saturation = 1
console.debug( camera.imageProcessing.saturation )

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The output is 0 instead of 1.

I'm facing this problem with all settings:

camera.imageProcessing.contrast = 1
console.debug( camera.imageProcessing.contrast)

camera.imageProcessing.contrast = 1
console.debug( camera.imageProcessing.contrast)

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The output is 0 instead of 1.

[wysota]

Have you tried setting the values by declaring them directly in the QML document?

[Pixtar]

Wysota I don't know exactly what you mean, but I've tried the following:

Item{
    Camera {
        id: camera
        imageProcessing.saturation: 1.0
        imageProcessing.contrast: 1.0
        ....
 
        imageCapture {
            onImageSaved: {
               console.debug( camera.imageProcessing.contrast )
            }
        }
    }
}

Item{
    Camera {
        id: camera
        imageProcessing.saturation: 1.0
        imageProcessing.contrast: 1.0
        ....

        imageCapture {
            onImageSaved: {
               console.debug( camera.imageProcessing.contrast )
            }
        }
    }
}

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I also tried it with a gui element:

Rectangle{
        property Camera camera
        id: mainRectangle
                Slider{
                    id: contrastSpin
                    minimumValue: -10.0
                    maximumValue: 10.0
                    value: 1
                    stepSize: 1
                    onValueChanged: {
                         camera.imageProcessing.contrast = value/10.0
                    }
                }
    }

Rectangle{
        property Camera camera
        id: mainRectangle
                Slider{
                    id: contrastSpin
                    minimumValue: -10.0
                    maximumValue: 10.0
                    value: 1
                    stepSize: 1
                    onValueChanged: {
                         camera.imageProcessing.contrast = value/10.0
                    }
                }
    }

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[wysota]

Maybe your camera simply does not allow modifying those values. At least the first approach should have worked otherwise.

[Pixtar]

For integrity here the main.cpp:

#include <QGuiApplication>
#include <QQmlComponent>
#include <QQmlContext>
#include <QObject>
#include <QQuickItem>
#include <QQuickView>
#include <QQuickImageProvider>
#include <QVariant>
#include <QCamera>
 
int main( int argc, char *argv[] ){
    QGuiApplication app( argc, argv );
 
    QQuickView view;
 
    view.setResizeMode( QQuickView::SizeRootObjectToView );
    view.setSource( QUrl("qrc:///QML/main.qml") );
 
    QObject *item = view.rootObject( );
 
    view.show( );
    return app.exec( );
}

#include <QGuiApplication>
#include <QQmlComponent>
#include <QQmlContext>
#include <QObject>
#include <QQuickItem>
#include <QQuickView>
#include <QQuickImageProvider>
#include <QVariant>
#include <QCamera>

int main( int argc, char *argv[] ){
    QGuiApplication app( argc, argv );
	
    QQuickView view;

    view.setResizeMode( QQuickView::SizeRootObjectToView );
    view.setSource( QUrl("qrc:///QML/main.qml") );

    QObject *item = view.rootObject( );
	
    view.show( );
    return app.exec( );
}

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An here the code for main.qml:

import QtQuick 2.2
import QtMultimedia 5.2
import QtQuick.Layouts 1.1
import QtQuick.Controls 1.1
import QtQuick.Dialogs 1.1
import "qrc:///QML"
 
Item {
    focus: true
    visible: true
    id: item
    Camera {
        id: camera
        captureMode: Camera.CaptureStillImage
        imageProcessing.saturation: -1.0
        imageProcessing.contrast: -1.0
    }
 
    Rectangle{
        id: rectangleImage
        visible: true
        ColumnLayout{
            spacing: 10
 
            Button{
                id: menuButton
                text: "Check Camera"
                onClicked: {
                    camera.imageProcessing.contrast = -1.0
                    console.debug( camera.imageProcessing.contrast )
                }
            }
 
            VideoOutput {
                id: output
                source: camera
                focus : visible
                visible: true
                autoOrientation: true
 
                anchors.fill: parent
 
                x: parent.height > parent.width ? 0 : parent.width/2*2
                y: parent.height > parent.width ? parent.height/2*2+5 : 0
 
                height: parent.height > parent.width ? parent.height/2 : parent.height/2
                width: parent.height > parent.width ? parent.width/2 : parent.width/2
            }
        }
    }
}

import QtQuick 2.2
import QtMultimedia 5.2
import QtQuick.Layouts 1.1
import QtQuick.Controls 1.1
import QtQuick.Dialogs 1.1
import "qrc:///QML"

Item {
    focus: true
    visible: true
    id: item
    Camera {
        id: camera
        captureMode: Camera.CaptureStillImage
        imageProcessing.saturation: -1.0
        imageProcessing.contrast: -1.0
    }

    Rectangle{
        id: rectangleImage
        visible: true
        ColumnLayout{
            spacing: 10

            Button{
                id: menuButton
                text: "Check Camera"
                onClicked: {
                    camera.imageProcessing.contrast = -1.0
                    console.debug( camera.imageProcessing.contrast )
                }
            }

            VideoOutput {
                id: output
                source: camera
                focus : visible
                visible: true
                autoOrientation: true

                anchors.fill: parent

                x: parent.height > parent.width ? 0 : parent.width/2*2
                y: parent.height > parent.width ? parent.height/2*2+5 : 0

                height: parent.height > parent.width ? parent.height/2 : parent.height/2
                width: parent.height > parent.width ? parent.width/2 : parent.width/2
            }
        }
    }
}

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