Task icon is blurred

[AndrzejB]

I have Ubuntu Cinnamon.
MainWindow icon in task bar (probably 32x32) is quite ok, but larger for Alt+Tab (probably 72x72) is blurred.
No matter, icon is svg, or 32x32 png, or 72x72 png or even 256x256 png
Note: Inkskape convert without blur - was exported without anti-aliasing , here png without blur:

by way:
is possible render SVG by Qt without antialiasing ?

MInimal example
CMakeLists.txt

cmake_minimum_required(VERSION 3.22)
project(minblur)

set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(CMAKE_CXX_STANDARD 14)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(Qt5 COMPONENTS Widgets REQUIRED)
qt5_add_resources(QRC_SOURCES icons.qrc)

set(PROJECT_SOURCES main.cpp)

add_executable(${PROJECT_NAME} ${PROJECT_SOURCES} ${QRC_SOURCES})

target_link_libraries(${PROJECT_NAME} Qt5::Widgets)

icons.qrc

<!DOCTYPE RCC>
<RCC version="1.0">
<qresource prefix="/">
    <file>line72.png</file>
</qresource>
</RCC>

main.cpp

#include <QApplication>
#include <QMainWindow>

class MainWindow: public QMainWindow {
public:
    explicit MainWindow(QWidget *parent = nullptr) {
        QIcon icon;
        icon.addFile(":line72.png", QSize(72, 72));
        setWindowIcon(icon);
    }
};

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);
    MainWindow w;
    w.show();
    return app.exec();
}

line72.pg :

Here is png, which is grayed and b;lured in Alt+Tab with Cinnamon

---

Solution: seems to be a Cinnamon thing, not Qt: If I add my binary to menu and add png as icon, is OK when I launch application from menu instead of direct binary.