Python 与 Qt c++ 程序共享内存,传递图片

python 代码

这里Python 使用 shared_memory
QT 使用 QSharedMemory

简单协议：
前面4个字节是图片with,height,0,0
后面是图片数据

import sys
import struct
def is_little_endian():x=0x12345678y = struct.pack('I',x)return y[0]==0x78print(f"is_little_endian:{is_little_endian()}")from multiprocessing import  shared_memory
import numpy as np
from PIL import Image
import matplotlib.pyplot as plt# 随机颜色 RGBA
def random_color()->tuple:rgba = np.random.randint(0,255,size=4)return tuple(rgba)# 用随机数填充像素
def fill_random_pixels(img):width, height = img.sizefor x in range(width):for y in range(height):img.putpixel((x, y), random_color())if __name__ == "__main__":# 选择随机图片或者加载本地图片 random_image=Falseimg_width = 100img_height = 100img = Image.new('RGBA', (img_width, img_height))if random_image:fill_random_pixels(img)origin_data = np.array(img)else:img_path = "C:\\Users\\mingxingwang\\Pictures\\qt-logo.png"# 打开图片并转换为numpy数组img = Image.open(fp=img_path)img = img.convert("RGBA")print(f"------------img.size------------:\n{img.size}\n")img_width,img_height = img.sizeorigin_data = np.array(img)origin_data = np.insert(origin_data,0,[img_width,img_height,0,0])print(f"------------img------------:\n{img}\n")print(f"------------origin_data------------:\n{origin_data}\n")print(f"------------origin_data.dtype------------:\n{origin_data.dtype}\n")#------------- 数据写入共享内存# 创建共享内存对象shm_a = shared_memory.SharedMemory(create=True, name="my_share_mem",size=origin_data.nbytes)#构造关联共享内存的数组mem_array = np.ndarray(origin_data.shape, dtype=origin_data.dtype, buffer=shm_a.buf)#copy 数据到共享内存mem_array[:]=origin_data[:]print(f"------------mem_array------------:\n{mem_array}\n")#显示原始图片origin_image = Image.frombytes(mode='RGBA',size=img.size,data=origin_data)plt.imshow(origin_image)plt.show()#------------- 共享内存获取数据existing_shm = shared_memory.SharedMemory(name='my_share_mem')array_from_mem = np.ndarray(origin_data.shape, dtype=origin_data.dtype, buffer=existing_shm.buf)print(f"------------array_from_mem------------:\n{array_from_mem}\n")##从共享内存构造图片img_from_mem = Image.frombytes(mode='RGBA',size=img.size,data=array_from_mem)##显示从共享内存获取的图片plt.imshow(img_from_mem)plt.show()shm_a.close()shm_a.unlink()

QT 程序

#include <QDebug>#include <QSharedMemory>
#include <QBuffer>
QSharedMemory *sm;sm = new QSharedMemory();// sm->setKey("my_share_mem");/// 与非Qt 程序通信 setNativeKeysm->setNativeKey("my_share_mem");if(!sm->attach()){qDebug()<<"attach error";return;}qDebug() << "attach success";QBuffer buffer;QImage image;sm->lock();buffer.setData((char*)sm->data(),sm->size());sm->unlock();sm->detach();if(!buffer.open(QBuffer::ReadOnly)){qDebug()<<"open buffer error";return;}// 按照传输协议,获取图片信息quint8 img_width , img_height ,other = 0;buffer.read((char*)&img_width,1);buffer.read((char*)&img_height,1);buffer.read((char*)&other,1);buffer.read((char*)&other,1);qDebug()<<"img_width:"<<img_width<<"img_height:"<<img_height<<"other:"<<other;// image bytes = width*height*4 (RGBA8888)uint len = img_width*img_height*4;uchar *p=(uchar*)buffer.data().data();printf("buffer[0]=%d,buffer[1]=%d,buffer[2]=%d,buffer[3]=%d \n",p[0],p[1],p[2],p[3]);fflush(stdout);//按照协议,从缓冲区构造图片image = QImage((uchar*)(p+4),img_width,img_height,QImage::Format_RGBA8888);qDebug()<<image;