實時圖像
寫了一個關於實時圖像滾動顯示的例子，做個記錄。
滾動算法：
難點：
將內存數據繪制到界面，需要用到QImage和QPixmap，使用QImage轉換一下，具體參見代碼。這個費了好大勁才弄出來（網上的資料大都很簡單，處理個QImage打開保存啊等等操作，項目實用性不強。）
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
經驗證，圖像“拖尾”比較嚴重，圖像滾動平滑效果比不上用DirectX做的效果，但是刷新效率很高，QT這塊做的比C#好很多。
下次，實用Opengl做一個，看看效果咋樣。