vdview Advanced Settings

The viewer is started with default settings. For normal use, these settings do not have to be changed. If the viewer is not working correctly it may be necessary to change some of the settings. The settings can accessed through the "Settings" button. See the section below for the description of each option.

Image Transfer

The image can be sent to the web browser using a secure or an insecure method. In general, the secure method is the default method and should always be used. If your particular web browser has trouble displaying images, the insecure method can be used.

Image Quality

The image quality setting specifies the amount of image compression to be used. (Images are displayed much faster when compression is used but some image detail may be lost). When the quality is set to 100, the GIF lossless compression is used and no data is lost. For any setting other than 100 JPEG lossy compression is used. For the default 75 setting very little image detail is lost. At the lowest setting 25 some compression artifacts may be visible.

Image Cache

An image cache is used to remember images that have already been loaded into the image viewer. If a cached image is available, then the viewer will use the cached image rather than loading the image from the web server. This will speed up the viewer when scrolling back and forth between images. By default, 50% of the applet available memory is used as image cache (tipically 32MB). The image cache size can be changed by selecting the "Set Image Cache..." menu from the Settings pop up-menu.

Loading Images

A different image for the current patient can be loaded by pressing the Open... button, if you ar not in compact mode, and then pressing the Browse Cases, if shown. This will bring up a list of studies and images grouped by date. Selecting an image and clicking Open will load the corresponding image in the java image viewer. Alternatively, double-clicking on the image line will load that image.

Settings Menu

The various options available in the Settings menu are shown below. Items that are grouped together in selection are grouped together in the table. Normally these options should not have to to be changed.

OptionDescription
No Interpolation Use no interpolation when displaying a magnified image. The magnified image will display faster but it will appear pixelated.
Bilinear Interpolation Use bilinear interpolation when displaying a magnified image. The image will be smoothed but it will display slower.
Bicubic Interpolation (default) Use bicubic interpolation when displaying a magnified image. The image will be smoothed but it will display slower.
Fast Panning (default on) Switch to no interpolation when panning the image. This will speed up the response of the image viewer. The interpolation method is switched back after panning is complete.
Fast Windowing (default on) Switch to no interpolation when dynamically windowing the image. This will speed up the response of the image viewer. The interpolation method is switched back after windowing is compete.
Secure Images (default) Get images by receiving them directly from the server. This is strongly recommended.
Insecure Images Get images by downloading them from the server. This is not recommended unless the image viewer is having trouble with the secure protocol.
8-bit Images (default) Use 8-bit images. This is the fastest option and is recommended. There is no difference in image quality between 8-bit, 16-bit, and 16-bit compressed image modes.
16-bit Images Use 16-bit images. Allows for dynamic windowing with the mouse.
16-bit Compressed Images Use 16-bit compressed images. The images on the server are compressed (no loss of image quality) before sending them to the image applet. Use this if the connection to the server is slow. Allows for dynamic windowing with the mouse.
Image Quality 100 (default) Use no lossy compression in 8-bit Image mode. There will be no loss in image quality. Loads the slowest.
Image Quality 75 Use lossy compression (75) in 8-bit Image mode. There is no visible difference when the image is not magnified. Some compression artifacts when the image is magnified.
Image Quality 50 Use lossy compression (50) in 8-bit Image mode. There is no visible difference when the image is not magnified. More compression artifacts when the image is magnified.
Image Quality 25 Use lossy compression (25) in 8-bit Image mode. Some loss of image quality when not magnified. Very bad compression artifacts when magnified. Loads the quickest.
Show Mouse Coords (default on) Show the coordinates of the mouse when it is over the image.The origin of the coordinate system is the bottom-left of the image.
Use narrow dialog box (default off) Use a narrow size dialog box (340 x 400). The default size is 500 x 400.
Display general image information ( default off ) Filenames of images in the study are listed in the case browser panel. In the default, DICOM study IDs of the images are listed.
Fit image in the display (default on) In this mode, an images with size smaller or larger than 512x512 is resampled to fit into the viewing window (512 x 512).
Set Image Cache Set the amount of memory used for the image cache. The default value is 8192 KB.
Auto Cache Image on Load (default off) Automatically cache 15 images when loading an image.
Debug Mode (default off) Show debugging information in the Java console.

Bugs and Notes

  • The checkboxes in the Settings Menu cannot be selected by clicking the mouse with Java 1.4 on Linux. Use the mouse to highlight the selection you want, then hit enter to select the item.
  • The scrollbar may be buggy with Java versions 1.2 and 1.3. It should be fine for Java 1.4 and Java 5.0 (the most recent version by Sun).