PdfPageImage should look good on high-dpi by default

                property size pagePointSize: document.pagePointSize(index)
                property real pageScale: image.paintedWidth / pagePointSize.width
                PdfPageImage {
                    id: image
                    document: root.document
                    currentPage: index
                    asynchronous: true
                    fillMode: Image.PreserveAspectFit
                    width: paper.pagePointSize.width * root.renderScale
                    height: paper.pagePointSize.height * root.renderScale
                    property real renderScale: root.renderScale
                    property real oldRenderScale: 1
                    onRenderScaleChanged: {
                        image.sourceSize.width = paper.pagePointSize.width * renderScale * Screen.devicePixelRatio
                        image.sourceSize.height = 0
                        paper.scale = 1
                        searchHighlights.update()
                        tableView.forceLayout()
                    }