Snowbound Software’s VirtualViewer web viewer and SnowView have several features that allow you to change the appearance of an image. One of these tools is the Alias/Anti-alias tool. This tech tip describes how to use the Alias/Anti-alias tool to improve the appearance of an image.
Aliasing is a process by which smooth curves and other lines become jagged because the resolution of the display or the graphic file is not high enough to represent a smooth curve. Anti-aliasing is a software technique used to diminish ‘step-like’ lines that should be smooth. Anti-aliasing surrounds stair steps with intermediate shades of gray, or gray scaling, for 1-bit images or color for color images.
The image below shows an example of aliasing and anti-aliasing:
In Snowbound Software’s VirtualViewer Applet, you can anti-alias images by using the Anti-alias feature. To turn aliasing on, select Preferences>Anti-alias>Scale to Gray or Preserve Black from the menu. This feature only works for black and white 1-bit images.
To turn aliasing off, select Preferences>Anti-alias>Off from the menu. This feature only works for black and white 1-bit images.
SnowView’s Alias/Anti-alias Tool
In Snowbound’s SnowView application, aliasing can be turned on or off by doing the following:
Choose View > Aliasing (This displays the Alias dialog.)
In the Type field, select None, Preserve Black, Scale to Gray, or Quality. (See the table below for a description of each alias type.)
Click OK to accept the changes, or click Cancel to avoid making any changes.
| Alias Type | Description |
| None | Aliasing is not turned on. |
| Preserve Black | Checks neighboring pixels for any black so that any small black lines are not removed when scaling a large black and white image. The Preserve Black option is typically recommended for large schematics and engineering drawings. |
| Scale to Gray | Converts the image to gray scale values when displaying a large image. The Scale to Gray option is typically recommended for documents. |
| Quality | Higher quality setting improves the quality of 1-bit (B&W) images. |