imagej - ImageJ - 宏：在窗口中更改值期间显示阈值

Question

要解决的问题：在编辑阈值时显示图像的变化：

function Process_image(dir_in, dir_out,IMG,Scale_){
    open(dir_in + IMG);
    W=getNumber("Width?", 670);
    H=getNumber("Height?", 400);
    run("Specify...", "width=W height=H centered scaled");
    run("Crop");
    contrast_scale=Get_Contrast_from_scale(Scale_);
    run("Enhance Contrast", "saturated=contrast_scale");
    run("Sharpen");
    run("Threshold...");//Issue to be solved: show image during editing...
    waitForUser("Press X at Threshold window. Then close this one for analyze.");
    saveAs("Tif", dir_out + IMG + "AP");
    IMG_after_pro = dir_out + IMG + "AP.tif";
    Analize_and_Sum(IMG_after_pro,dir_out);
    Analize_and_Sum2(IMG_after_pro,dir_out);
    close();
}

此功能按预期工作；但是，我在编辑它的阈值时看不到图片。我应该怎么办？没有看到图片，我的代码没用......