Loading Image in DocumentGalleryModel takes extremely long time

wladek

Hi Guys,

I am trying to use the "QML DocumentGalleryModel":http://doc.qt.nokia.com/qtmobility-1.1.1/qml-documentgallerymodel.html with the following code (on my Symbian N8 device):
@importQt 4.7
import QtMobility.gallery 1.1

Rectangle {
width: 600
height: 360
color: "lightblue"

GridView {
    id: gridView
    anchors.fill: parent
    cellWidth: 128
    cellHeight: 128

    model: DocumentGalleryModel {
        rootType: DocumentGallery.Image
        properties: [ "url" ]
    }

    delegate:
        Item {
            Image {
                id: imageBusy
                source: "busy.png"
                width: 110
                height: 110
                sourceSize.width: 110
                sourceSize.height: 110
                visible: imageDelegate.status != Image.Ready
            }
            Image {
                id: imageDelegate
                asynchronous: true
                source: url
                smooth: true
                width: 110
                height: 110
                fillMode: Image.PreserveAspectFit
                sourceSize.width: 110
                sourceSize.height: 110
                onStatusChanged: {
                    console.log("Status is: " + status);
                }
            }
    }
}

}@

The problem is that displaying the images takes super long time (for just 20 images it takes around 10 seconds).

Any ideas on how can I improve this time?

I also know that drawing the image is problematic, hence retrieving the data from the model goes straight forward. It's also true that the images have a big resolution (aprox. 4000 x 2000).

Any leads are highly appreciated.

Thanks in advance and regards,
Wladek

[edit: fixed typo in title, Eddy]

andre

Well, those images are rather big. Does it help to disable smooth?

wladek

No noo....I already tried this. No improvement at all.

pdrummond

I've had the same problem except I couldn't get photo's taken from a C7 to display at all because of their size. All I got was the following error:

@QVGImagePool: cannot reclaim sufficient space for a 3264x1832 image@

To get around this problem it is possible to scale the image down by setting the Image.sourceSize to a lower size than the actual image.

QtRoS

First of all, set asynchronous property of Image in delegate to true. Then use sourceSize property to set optimal size of image. Result - Image of this size will be loaded in memory asynchronously! So UI will not be blocked!