aspjpeg缩小图片的组件使用介绍（2）

Adjusting Image Compression (advanced users only)
The JPEG format uses "lossy" compression methods. This means that some minor details of an image saved as a JPEG are lost during compression. The degree of loss can be adjusted via the jpeg.Quality property. This property accepts an integer in the range 0 to 100, with 0 being the highest degree of loss (and hence, the lowest quality) and 100 being the lowest degree of loss and highest quality.
The lower the loss, the larger the resultant file size. The property jpeg.Quality is set to 80 by default which provides a close-to-optimal combination of quality and file size. Changing this property is generally not recommended.
AspJpeg Object Reference
AspJpeg Properties
Expires As Date (read-only)
Returns the component's expiration date. If a valid registration key is installed, returns 9/9/9999.
Height As Long (read/write)
Specifies a new image height (in pixels). Must be called after an image is opened via the Open method.
Interpolation As Long (read/write)
Specifies an image resizing algorithm. The following values are currently supported: 0 (Nearest-Neighbor), 1 (Bilinear, default) and 2 (Bicubic).
The Nearest-Neighbor (NN) is the fastest but provides low-quality thumbnails.
The Bilinear method offers much better thumbnail quality but is approximately 2 times as slow as NN.
The Bicubic method is approximately twice as slow as Bilinear and 4 times as slow as NN, but supposedly offers the highest quality. In many cases, however, it provides little, if any, noticeable improvement over the Bilinear method.
Default: 1 (Bilinear).
OriginalHeight As Long (read-only)
Returns the original image height (in pixels). Can only be called after an image is opened via the Open method. Use this property to preserve the original aspect ratio of an image.
OriginalWidth As Long (read-only)
Returns the original image width (in pixels).Can only be called after an image is opened via the Open method. Use this property to preserve the original aspect ratio of an image.