@GrecKo the problem is, that GridView releases it delegates when model's elements is removed. It provokes Image to reload if delegate is shown again. No meter if I set cache: true Such a shame that GridView don't have reuseItems like ListView I've come with next decision. I've created Repeater containing Image that use source model. GridView's delegate Image use Repeater's function itemAt() giving delegate's index after mapping to source model: //Image in deleagte Image { Component.onCompleted: { source = appModelImages.loadImage(appFilterModel.mapRowToSource(parent.delegateIndex)) // custom implementation } ... } //Repeater Repeater { id: appModelImages visible: false function loadImage(index){ return itemAt(index).source } model: AppModel delegate: Image { visible: false asynchronous: true source: model.boxart } } This may be not the best decision, but "faster" than create own delegate pool for GridView. Didn't see any examples of implementing mechanism like this. Repeater should work fine, as it relays on source model. And as I expected, images live when source model does.

You're right. Thanks for answering. I finally ended with a QImageProvider. My image provider takes a filename followed by a question mark and a color (image://myimageprovider/myicon.svg?red). I can then colorize my svg file (this is why i needed a new Image() ) from my image provider. This is the qml part. import QtQuick 2.11 Canvas { width: 200 height: 200 property string imageUrl: "image://myimageprovider/myicon.svg?red" Component.onCompleted: loadImage(imageUrl) onImageLoaded: requestPaint(); onPaint: { var ctx = getContext("2d"); ctx.drawImage(imageUrl, 0, 0, 32, 32); } }

Here is the reason and solution. Thanks to Marti Maria - the author of littlecms - to sort this out ... This program does not work because you missed the part on https://littlecms.com/blog/2020/12/09/using-lcms2-on-qt/ that says: Alpha channels are supported as long as the image is not using premultiplied alpha. To get alpha channel make sure to include cmsFLAGS_COPY_ALPHA in the flags field. This is explained in LittleCMS documentation. So, try: toDisplay = colorManage(sourceImage, profiles, INTENT_PERCEPTUAL, cmsFLAGS_COPY_ALPHA);* This fixed the issue for me.

@Nick-Redwill This is what windeployqt is for...

Hi and welcome to devnet, You can't jump from a 32bit float image to 16bit integer one like that. Convert your OpenCV image to 16 bit before making a QImage out of it.

Did you consider using the QtGraphicalEffects module ?

QImage::save() doesn't get the raw bytes of the image, it converts the image to a file format. If you really want the raw bytes, do something like QByteArray ba((const char *)preview.constBits(), preview.byteCount());

@Kent-Dorfman thanx for reply. Actually I saw few java script programs for pointing accurate pixel values on image by using Mercator projection and it's formula. I checked it works fine in Java script. But in qt I want to display whole lat long trace so wanted to plot chart with image as it's background. But not able to correctly det the background image as per chart x and y axis values.

Is it possible to to extend QLabel and implement my own paintEvent() that draws the text and draws the svg image? It seems to work, but would problaby take alot of effort to get it right (i.e. to get the image in the right location everytime). void MypLabel::paintEvent(QPaintEvent* event) { QPainter painter(this); const auto pos = QPoint(0, 16); painter.drawText(pos, this->text()); const auto posPixMap = QPoint(30, 0); auto size = QSize(16, 16); auto pixMap = QIcon(":/Resources/smiley.svg").pixmap(size); painter.drawPixmap(posPixMap, pixMap); }

@Omar-Medhat Show your current void MainWindow::on_openImage_clicked() implementation. The previous one was wrong as @SGaist pointed out...

@mrjj I see, thank you. I'm going for that route then

Hi @newbisoso , See this, it may help you

@KillerSmath That solved my problem. Thanks!

@krzysieklfc said in Gamma correction for display: Shouldn't Qt somehow handle the color correction when I'm 'telling it' to view the image? no! why should it? I don't quite understand why you are dividing by 256? Also whats the returning type of GetR()/GetG()/GetB()?