如何使用Fireworks脚本导出具有单个IDAT块的png？

Question

我可以使用以下导出参数使用JavaScript Fireworks（JSF）导出32位PNG文件：

exportFormatOptions:{
    name:"PNG size 440",
    xSize:440,
    ySize:440,
    cropTop:0,
    crop:false,
    sorting:"none",
    exportFormat:"PNG",
    paletteEntries:null,
    numGridEntries:6,
    ditherPercent:100,
    jpegSmoothness:0,
    jpegSubsampling:0,
    jpegSelQuality:90,
    percentScale:100,
    progressiveJPEG:false,
    interlacedGIF:false,
    animAutoCrop:true,
    localAdaptive:true,
    webSnapAdaptive:false,
    lossyGifAmount:0,
    jpegSelQualityEnabled:false,
    jpegSelPreserveButtons:false,
    savedAnimationRepeat:0,
    numCustomEntries:0,
    numEntriesRequested:0,
    paletteTransparency:"none",
    webSnapTolerance:14,
    jpegSelPreserveText:true,
    animAutoDifference:true,
    macCreator:"",
    macFileType:"",
    colorMode:"32 bit",
    paletteMode:"adaptive",
    paletteInfo:null,
    ditherMode:"none",
    jpegQuality:80,
    cropLeft:0,
    cropBottom:0,
    cropRight:0,
    applyScale:true,
    useScale:false,
    optimized:true,
    frameInfo:[]
}

但是它会根据分辨率将图像数据导出为多个IDAT块。

EG。 440x440 PNG有10个块，160x160 PNG有5个块等等。如何控制图像数据导出的块数？我可以在脚本中添加一些导出选项参数吗？