使用OpenCV调整图像数组大小 [英] Resize an array of images with OpenCV

问题描述

我使用OpenCV将一个图像数组（IplImage **）传递给C ++中的一个对象。然后我试图迭代该数组，并将它们调整为固定大小（150x150）

I'm passing an array of images (IplImage**) to an object in C++ using OpenCV. I'm then trying to iterate over that array and resize them all to a fixed size (150x150)

我这样做：

for(int i = 0; i< this->numTrainingFaces; i++)
{
    IplImage* frame_copy = cvCreateImage( cvSize(150,150), this->faceImageArray[0]->depth, this->faceImageArray[0]->nChannels );
    cout << "Created image" << endl;
    cvResize(this->faceImageArray[i], frame_copy);
    cout << "Resized image" << endl;
    IplImage* grey_image = cvCreateImage( cvSize( frame_copy->width, frame_copy->height ), IPL_DEPTH_8U, 1 );
    cout << "Created grey image" << endl;
    cvCvtColor( frame_copy, grey_image, CV_RGB2GRAY );
    cout << "Converted image" << endl;
    this->faceImageArray[i] = grey_image;
    cvReleaseImage(&frame_copy);
    cvReleaseImage(&grey_image);
}

但是我得到这个输出，我不知道为什么：

But I'm getting this output, and I'm not sure why:

Created image
Resized image
Created grey image
Converted image
Created image
OpenCV Error: Assertion failed (src.type() == dst.type()) in cvResize, file /build/buildd/opencv-2.1.0/src/cv/cvimgwarp.cpp, line 3102
terminate called after throwing an instance of 'cv::Exception'
  what():  /build/buildd/opencv-2.1.0/src/cv/cvimgwarp.cpp:3102: error: (-215) src.type() == dst.type() in function cvResize

Aborted

$ b b

我基本上只是尝试用尽可能少的步骤来替换数组中的图像。

I'm basically just trying to replace the image in the array with the resized one in as few steps as possible.

编辑：

修改我的代码如下：

for(int i = 0; i< this->numTrainingFaces; i++)
{

    IplImage* frame_copy = cvCreateImage( cvSize(150,150), this->faceImageArray[i]->depth, this->faceImageArray[i]->nChannels );
    cvResize(this->faceImageArray[i], frame_copy);
    IplImage* grey_image = cvCreateImage( cvSize( frame_copy->width, frame_copy->height ), IPL_DEPTH_8U, 1 );
    cvCvtColor( frame_copy, grey_image, CV_RGB2GRAY );
    faceImageArray[i] = cvCreateImage( cvSize(grey_image->width, grey_image->height), grey_image->depth, grey_image->nChannels);
    cvCopy(grey_image,faceImageArray[i]);

    cvReleaseImage(&frame_copy);
    cvReleaseImage(&grey_image);
}

然后稍后我正在执行一些PCA， / p>

Then later on I'm performing some PCA, and get this output:

OpenCV Error: Null pointer (Null pointer to the written object) in cvWrite, file /build/buildd/opencv-2.1.0/src/cxcore/cxpersistence.cpp, line 4740

但我不认为我的代码有到我明确调用cvWrite的点，所以它必须是库的一部分。

But I don't think my code has got to the point where I'm explicitly calling cvWrite, so it must be part of the library. I can give a full implementation if necessary - is there anything in my code that's going to create a null pointer?

我的完整源代码在这里： http://pastie.org/1447022 - 创建一个类，设置变量，然后调用learn（）。

My full source code is here: http://pastie.org/1447022 - a class is created, variables are set, then learn() is called.

推荐答案

• 为什么在使用C ++时使用C接口？


• 您的错误很简单 - 您的图片在类型上有所不同，因此您无法使用类型从所有图片的第一张图片。



行

IplImage* frame_copy = cvCreateImage( cvSize(150,150), this->faceImageArray[0]->depth, this->faceImageArray[0]->nChannels );

应为

IplImage* frame_copy = cvCreateImage( cvSize(150,150), this->faceImageArray[i]->depth, this->faceImageArray[i]->nChannels );

另外， this-> 无操作。 faceImageArray [0] - > depth，faceImageArray [0] - > nChannels 应该足够了。

Also, this-> is usually a no-op. faceImageArray[0]->depth, faceImageArray[0]->nChannels should suffice.

这篇关于使用OpenCV调整图像数组大小的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！