QImage::scaled方法报错“image is a null image”的问题,以下是详细的解答和可能的解决方案: 确认QImage对象是否已正确加载图像: 在使用QImage的scaled方法之前,必须确保图像已经成功加载到QImage对象中。可以通过检查QImage的isNull()方法返回值来确认图像是否加载成功。
This is an overloaded function. Returns a copy of the image scaled to a rectangle with the givenwidthandheightaccording to the given AspectRatioModeand TransformMode. If either thewidthor theheightis zero or negative, this function returns a null image. 这是一个重载函数,按照指定的宽和高,根据...
g.flashDir( QFileInfo(fileName).dir().absolutePath() );if(!ui->useFwImageCB->isChecked()) { QImage image = ui->imageLabel->pixmap()->toImage().scaled(ui->imageLabel->width(), ui->imageLabel->height());if(!image.isNull()) { QString tempDir = QDir::tempPath(); QString te...
image =newQImage(QString(inFile->filename));if(image->isNull()) {deleteimage;returnIIERR_NOT_FORMAT; }if(image->depth() <8) {deleteimage; b3dError(NULL,"%s is a recognized file type but data type is not ""supported\n", inFile->filename);returnIIERR_NO_SUPPORT; }if(inFile->fp...
QImage scaled ( const QSize & size, Qt::AspectRatioMode aspectRatioMode = Qt::IgnoreAspectRatio, Qt::TransformationMode transformMode = Qt::FastTransformation ) const QImage scaled ( int width, int height, Qt::AspectRatioMode aspectRatioMode = Qt::IgnoreAspectRatio, Qt::TransformationMode transform...
scaled(QSize(img.width() / 2, img.height() / 2)); // 遍历每一个像素点 for(int i=0; i<img.width(); i++) { for(int j=0; j<img.height(); j++) { //设置灰度化:每个rgb分量设置为一样 QRgb rgb = img.pixel(i, j); int r = qRed(rgb); int g = qGreen(rgb); int ...
一、图像格式间相互转换1.BYTE转QImage、HObject和MatBalser下相机图像数据转换成QImage、Mat、HObject {代码...} 2.QImage、HObject和Mat的相互转换QImage转...
另请参见isNull()和Image Transformations。 QImage QImage :: scaled( int width, int height, Qt :: AspectRatioMode aspectRatioMode = Qt :: IgnoreAspectRatio, Qt :: TransformationMode transformMode = Qt :: FastTransformation)const 这是一个过载功能。
但是又有新问题了 转换前和转换后每一个像素里面的数据都一摸一样 为啥就显示不一样呢 ...
self.update_item.emit(book_id)returncdata =Noneifp.isNull()elsepifnotuse_cache:# cache is staleifcdataisnotNone: width, height = p.width(), p.height()scaled, nwidth, nheight = fit_image( width, height, page_width, page_height)ifscaled:ifself.ignore_render_requests.is_set():return...