def render(self):
# Convert data to QImage for display.
profile = debug.Profiler()
if self.image is None or self.image.size == 0:
return
if isinstance(self.lut, collections.Callable):
lut = self.lut(self.image)
else:
lut = self.lut
if self.autoDownsample:
# reduce dimensions of image based on screen resolution
o = self.mapToDevice(QtCore.QPointF(0,0))
x = self.mapToDevice(QtCore.QPointF(1,0))
y = self.mapToDevice(QtCore.QPointF(0,1))
w = Point(x-o).length()
h = Point(y-o).length()
if w == 0 or h == 0:
self.qimage = None
return
xds = max(1, int(1.0 / w))
yds = max(1, int(1.0 / h))
axes = [1, 0] if self.axisOrder == 'row-major' else [0, 1]
image = fn.downsample(self.image, xds, axis=axes[0])
image = fn.downsample(image, yds, axis=axes[1])
self._lastDownsample = (xds, yds)
else:
image = self.image
# if the image data is a small int, then we can combine levels + lut
# into a single lut for better performance
levels = self.levels
if levels is not None and levels.ndim == 1 and image.dtype in (np.ubyte, np.uint16):
if self._effectiveLut is None:
eflsize = 2**(image.itemsize*8)
ind = np.arange(eflsize)
minlev, maxlev = levels
levdiff = maxlev - minlev
levdiff = 1 if levdiff == 0 else levdiff # don't allow division by 0
if lut is None:
efflut = fn.rescaleData(ind, scale=255./levdiff,
offset=minlev, dtype=np.ubyte)
else:
lutdtype = np.min_scalar_type(lut.shape[0]-1)
efflut = fn.rescaleData(ind, scale=(lut.shape[0]-1)/levdiff,
offset=minlev, dtype=lutdtype, clip=(0, lut.shape[0]-1))
efflut = lut[efflut]
self._effectiveLut = efflut
lut = self._effectiveLut
levels = None
# Assume images are in column-major order for backward compatibility
# (most images are in row-major order)
if self.axisOrder == 'col-major':
image = image.transpose((1, 0, 2)[:image.ndim])
argb, alpha = fn.makeARGB(image, lut=lut, levels=levels)
self.qimage = fn.makeQImage(argb, alpha, transpose=False)
评论列表
文章目录
