因此,我正在使用QT为我的类(class)进行图像操作分配,要求我将当前拥有的图像数据手动保存为PPM格式,然后将其重新加载到QDialog程序中。
我设法正确保存了图像(使用gimp验证了输出文件),但是从文件中加载造成了如下所示的灾难
这是原始文件:
以及不良的负载:
这是我的文件加载代码:
//... opens the file and pulling out headers & etc...
unsigned char* data = new unsigned char[width*height*3];
//Manual loading each byte into char array
for(long h = 0; h < height; h++){ //for all 600 rows
getline(readPPM,temp); //readPPM is an ifstream, temp is a string
std::stringstream oneLine(temp);
for(long w = 0; w < width*3; w++){ //to every position in that line 800*3
int readVal;
oneLine >> readVal; //string stream autofill get the int value instead of just one number
data[width*h+w] = (unsigned char)readVal; //put it into unsign char
}
}
//Method 1: create the QImage with constructor
(it blacked out 2/3 of the bottom of the image, and I'm not exactly familiar with QImage data type)
imageData = QImage(data,width,height,QImage::Format_BGR888);
//Method 2: manually setting each pixel
for(int h = 0; h < height; h++){
for(int w = 0; w < width; w++){
int r,g,b;
r = (int)data[width*h+w*3];
g = (int)data[width*h+w*3+1];
b = (int)data[width*h+w*3+2];
QColor color = qRgb(r,g,b);
imageData.setPixelColor(w,h,color);
}
}
//...set image to display...
从文件加载时,我希望显示的图像看起来像原始图像,并且不确定导致损坏的问题是什么,请帮助
最佳答案
一行图像的大小为3 * width
字节,而不是width
,因此应在data[]
索引中的所有位置固定该大小。
即码
data[width*h+w] = (unsigned char)readVal;
应该替换为data[3*width*h+w] = (unsigned char)readVal;
和代码r = (int)data[width*h+w*3];
g = (int)data[width*h+w*3+1];
b = (int)data[width*h+w*3+2];
替换为r = (int)data[3*width*h+w*3];
g = (int)data[3*width*h+w*3+1];
b = (int)data[3*width*h+w*3+2];
关于c++ - 从PPM文件加载的QImage无法正确显示,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/63911585/