Black-and-white images 
Are scaled to gray.
Palettized 4- and 8-bit, RGB, and BGR images Remain color images.
| Example-VB | Example-VC++ |
Returns or sets the scaling algorithm used when displaying images. It is particularly useful for implementing scale-to-gray functionality.
| Ö | Imaging for Windows Professional Edition V1.0, V1.1, and V2.0 |
| Ö | Imaging for Windows 95 and 98 |
| Ö | Imaging for Windows NT 4.0 |
Image Edit control
object.DisplayScaleAlgorithm[=value]
Integer (enumerated)
Property settings are expressed using the following values:
| Constant | Setting | Description | Notes |
| wiScaleNormal | 0 (default) | Normal | Normal decimation. All page types remain unchanged. |
| WiScaleGray4 | 1 | Gray4 | 4-bit gray-scale, 16 shades of gray. All page types are scaled to gray. |
| WiScaleGray8 | 2 | Gray8 | 8-bit gray-scale, 256 shades of gray. All page types are scaled to gray. |
| WiScaleStamp | 3 | Stamp | Used for thumbnail representation of images |
| wiScaleOptimize | 4 | Optimize | Changes the display algorithm based on the page type of the displayed image:
Black-and-white images
Palettized 4- and 8-bit, RGB, and BGR images |
The DisplayScaleAlgorithm value can be specified before or after an image is displayed. If the value is specified after an image is displayed, the displayed image may change visually. Note that when scaling from normal decimation to another setting, the displayed image remains unchanged.
When the AutoRefresh property is set to True, changing the DisplayScaleAlgorithm property causes the displayed image to be refreshed automatically. Some settings may not be apparent until the image is scaled to a Zoom value under 100 percent.