Ios - ImageMagick - No Image Created after Distortion

Question

I am new To ImageMagick, and in my iOS App i want to apply Shepard Distortion on a image and get back UIimage i am Coding as Follows

-(void)distortImage{

    MagickWandGenesis();
    MagickWand * wand;
    MagickBooleanType status;

    wand = NewMagickWand();
    MagickSetFormat(wand, "png");
    status = MagickReadImage(wand,"chess.png");

    // Arguments for Shepards
    double points[8];
    points[0] = 250; // First X point (starting)
    points[1] = 250; // First Y point (starting)
    points[2] =  50; // First X point (ending)
    points[3] = 150; // First Y point (ending)
    points[4] = 500; // Second X point (starting)
    points[5] = 380; // Second Y point (starting)
    points[6] = 600; // Second X point (ending)
    points[7] = 460; // Second Y point (ending)


    MagickDistortImage(wand,ShepardsDistortion,8,points,MagickFalse);
    NSString * tempFilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"out.png"];
    MagickWriteImage(wand,[tempFilePath cStringUsingEncoding:NSASCIIStringEncoding]);
    UIImage * imgObj = [UIImage imageWithContentsOfFile:tempFilePath];
    _resultImgView.image=imgObj;

//    
//    unsigned char * cBlob;
//    size_t data_size;
//    cBlob = MagickGetImageBlob(wand, &data_size);
//    NSData * nsBlob = [NSData dataWithBytes:cBlob length:data_size];
//    UIImage *uiImage = [UIImage imageWithData:nsBlob];
//    _resultImgView.image=uiImage;

    MagickWriteImage(wand,"out.png");
    wand=DestroyMagickWand(wand);
    MagickWandTerminus();
}

I tried to get Image in This way, but then i check for image at PATH there is file created with 0Byte and even UIimage imgObj is also nil. I dont know much imageMagick, help in this Code is also from

ios - ImageMagick How to code to apply ShepardsDistortion on image

but i need some coding help to get my UIImage Object.