c - Imagemagick Magickcore 抛出断言错误

Question

下面的代码抛出一个错误，我不明白为什么。

错误:核心:magick/compare.c:1003:GetImageChannelDistortion:断言“扭曲!= (double *) ((void *)0)”失败。

我正在尝试将此命令行语句转换为 magickcore 代码，

compare -dissimilarity-threshold 1 -metric MSE image1.jpg image2.jpg NULL

注意:我无法调试 imagemagick，它没有安装在环境中，而且我无权安装它。

版本:ImageMagick 6.5.4-7 2012-04-10

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <magick/MagickCore.h>

int main(int argc,char **argv)
{
    ExceptionInfo     *exception;
    Image             *base_image, *reference_image, *composed_image;
    double            * similarity = (double *) NULL;
    ImageInfo         *image_info, *image_info1;

    MetricType         metric = MeanSquaredErrorMetric;
    ChannelType        channel = AllChannels;
    MagickBooleanType  aaaa;

    char base_image_src[] = "jpgs/100000.jpg";
    char reference_image_src[] = "jpgs/101201.jpg";

    MagickCoreGenesis(NULL, MagickTrue);
    exception = AcquireExceptionInfo();

    image_info = CloneImageInfo((ImageInfo *) NULL);
    (void) strcpy(image_info->filename, base_image_src);
    base_image = ReadImage(image_info, exception);

    image_info1 = CloneImageInfo((ImageInfo *) NULL);
    (void) strcpy(image_info1->filename, reference_image_src);
    reference_image = ReadImage(image_info1, exception);

    if (exception->severity != UndefinedException) {
        CatchException(exception);
    }
    if (base_image == (Image *) NULL) {
        exit(1);
    }
    if (reference_image == (Image *) NULL){
        exit(1);
    }

    if (similarity != (double *) NULL)  {
        printf("whyyyyyyy\n");
    }

    aaaa = GetImageChannelDistortion(base_image, reference_image, channel, metric, similarity, exception);

    // Throws same double not null error
    //similarity = GetImageChannelDistortions(base_image, reference_image,  metric, exception);

    // Gives me an answer of 0.0 which is not what I'm looking for
    //composed_image = CompareImageChannels(base_image, reference_image, channel, metric, similarity, exception);

    printf("After:  %f\n", similarity);

    image_info=DestroyImageInfo(image_info);
    image_info1=DestroyImageInfo(image_info1);
    exception=DestroyExceptionInfo(exception);
    MagickCoreTerminus();
    return(0);
}

Answer 1

您应该通过地址传递相似度:

double similarity;
aaaa = GetImageChannelDistortion(base_image, reference_image, channel, metric, &similarity, exception);