def __init__(self, image, parent=None):
super(ToolWidget, self).__init__(parent)
max_q = 101
progress = QProgressDialog(self.tr('Computing residuals...'), None, 0,
max_q, self)
progress.setWindowModality(Qt.WindowModal)
loss_series = QtCharts.QLineSeries()
gray = cv.cvtColor(image, cv.COLOR_BGR2GRAY)
for q in range(max_q):
loss = cv.mean(cv.absdiff(compress_jpg(gray, q, color=False),
gray))
loss_series.append(q, loss[0])
progress.setValue(q)
progress.setValue(max_q)
loss_chart = QtCharts.QChart()
loss_chart.legend().hide()
loss_chart.setTitle(self.tr('Loss vs Compression'))
loss_chart.addSeries(loss_series)
loss_chart.createDefaultAxes()
loss_chart.axisX().setRange(0, 100)
loss_chart.axisX().setTitleText(self.tr('quality (%)'))
loss_chart.axisX().setTickCount(11)
loss_chart.axisX().setLabelFormat('%d')
loss_chart.axisY().setTitleText(self.tr('loss (%)'))
loss_chart.setMinimumSize(600, 400)
font = loss_chart.titleFont()
font.setBold(True)
loss_chart.setTitleFont(font)
loss_view = QtCharts.QChartView(loss_chart)
loss_view.setRenderHint(QPainter.Antialiasing)
main_layout = QVBoxLayout()
main_layout.addWidget(loss_view)
self.setLayout(main_layout)
def preprocess(self):
quality = self.quality_spin.value()
self.compressed = compress_jpg(self.image, quality)
self.process()