|
实时图像 写了一个关于实时图像滚动显示的例子，做个记录。
滚动算法： 难点： 将内存数据绘制到界面，需要用到QImage和QPixmap，使用QImage转换一下，具体参见代码。这个费了好大劲才弄出来（网上的资料大都很简单，处理个QImage打开保存啊等等操作，项目实用性不强。）
from PIL import Image import numpy as np import threading import time
class GraphicWidget(QWidget): def __init__(self): super(GraphicWidget,self).__init__() self.threadStop = False self.drawWidth = 1080 self.drawHeight = 800 self.imgWholeData = None self.imgScreenData = np.zeros([self.drawHeight,self.drawWidth],np.uint8) self.imgTotalLines = 0 self.imgWidth = 0 self.threadStop = True pass
def doscroll(self):
if self.threadStop: img = Image.open("d:/test2.png") self.imgWholeData = np.array(img) self.imgTotalLines, self.imgWidth = self.imgWholeData.shape
scrollThread = threading.Thread(target = self.scroll) scrollThread.start()
def stop(self): self.threadStop = True
def scroll(self): step = 5 srcStartLine = 0 srcEndLine = step destEndLine = step self.threadStop = False while not self.threadStop: if destEndLine > self.drawHeight: destEndLine = self.drawHeight
if srcEndLine > self.drawHeight: srcStartLine = srcEndLine - self.drawHeight
if srcEndLine > self.imgTotalLines: print("scroll end") self.threadStop = True break if srcStartLine < self.drawHeight: self.imgScreenData = np.zeros([self.drawHeight,self.drawWidth],np.uint8)
self.imgScreenData[0:destEndLine] = self.imgWholeData[srcStartLine:srcEndLine]
self.update()
destEndLine = destEndLine + step srcEndLine = srcEndLine + step
time.sleep(0.005) pass
def paintEvent(self,event): try: painter = QPainter() destRect = QRect(0,0,self.drawWidth,self.drawHeight) srcRect = QRect(0,0,self.drawWidth,self.drawHeight) img = QImage(self.imgScreenData.data, self.drawWidth, self.drawHeight, QImage.Format_Indexed8) pix = QPixmap.fromImage(img) painter.begin(self) painter.drawPixmap(destRect, pix, srcRect) painter.end() except Exception as e: print(e) raise
Pass
经验证，图像“拖尾”比较严重，图像滚动平滑效果比不上用DirectX做的效果，但是刷新效率很高，QT这块做的比C#好很多。
下次，实用Opengl做一个，看看效果咋样。
四更山吐月，夜半水明楼。
| 
