WIA: no compression when saving files

问题

I'm using WIA for scanning images and noticed, that images aren't stored efficiently as SaveFile apparently doesn't make use of compression.

Currently I'm using this code:

WIA.ImageFile img = (WIA.ImageFile)item.Transfer(WIA.FormatID.wiaFormatPNG);
img.SaveFile(path); 

Is there a way to use WIA for compression, or how else could I save the image using compression?

EDIT:

Using the following code I was able to decrease file size from 25 to 10 MB.

WIA.ImageFile img = (WIA.ImageFile)item.Transfer(WIA.FormatID.wiaFormatPNG);
WIA.ImageProcess ImageProcess1 = new WIA.ImageProcessClass();
System.Object Object1 = null;
System.Object Object2 = null;
Object1 = (Object)"Convert";
ImageProcess1.Filters.Add(ImageProcess1.FilterInfos.get_Item(ref Object1).FilterID, 0);
Object1 = (Object)"FormatID";
Object2 = (Object)WIA.FormatID.wiaFormatPNG;
ImageProcess1.Filters[1].Properties.get_Item(ref Object1).set_Value(ref Object2);
img = ImageProcess1.Apply(img);
img.SaveFile(path); 

回答1:

Basically you should add a compression filter before you save your image, in this url you can find a sample of tiff/jpg compression:

http://www.debugging.com/bug/18157

回答2:

After you have gotten your WIA Image (shown here as the 'image' variable), you apply a filter to adjust quality, before saving, like so:

WIA.ImageProcess myip = new WIA.ImageProcess();  // use to compress jpeg.
myip.Filters.Add(myip.FilterInfos["Convert"].FilterID);
myip.Filters[1].Properties["FormatID"].set_Value(WIA.FormatID.wiaFormatJPEG);
myip.Filters[1].Properties["Quality"].set_Value(jpgQuality);

image = myip.Apply(image);  // apply the filters
image.SaveFile(outputFilename);

In this example, jpgQuality is an int value between 1 and 100. 1 = low quality, 100 = best.

来源：https://stackoverflow.com/questions/10508974/wia-no-compression-when-saving-files