Image quality is a highly subjective topic – what may work for one office may not work for others, which means in many cases, filters need to be adjusted per office and per brand of device. This document will cover general post-capture filter adjustment steps, what filters should be used for different scenarios, as well as device specific settings.
In general, we recommend using post-capture filters rather than real-time filters in XVWeb as the primary method of improving image quality. This is not the case for all devices (see Device Specific Settings); however, most will benefit from post-capture filter adjustment. Adjusting post-capture filters allow for the returned image to be filtered and diagnostic as soon as the image returns, eliminating the need to apply any real-time filtering.
Post-Capture Filters are per brand of sensor, per workstation. They are accessed by going to Advanced User Tools > Preferences > Imaging Extensions > Drop-down digital x-ray image capture > select the device extension corresponding to the device producing poor quality > Image Quality Settings > Modify Post Capture Filters.
There are a number of devices that will not use any post-capture filters or require a complete rework of the default post-capture filters - If using any of the following brands of devices, please refer to the “device specific settings” portion of this guide:
- Schick
- Kodak/Carestream
- Kavo/Dexis/Gendex
- Instrumentarium
- Jazz
- Vatech
- E2V sensors (Tuxedo A Series, Quickray, Dentiray 4, XDR, etc.)
Post-Capture Filters - What filters to use, and when
Gamma Correction: Likely the most important and most used filter. Affects the lightness and darkness of an image using a “curve.” This allows for the ability to darken images while still enabling light areas of an image to remain light compared to the rest of the image, and lighten images while enabling dark areas of the image to remain dark compared to the rest of the image.
This is almost always used instead of a “brightness” filter.
Base value: 1.00. Lowering this value darkens the image, while raising this value lightens the image. For example, if no gamma filter is applied in the post-capture filters, adding one with a value of 0.80 (80 when entering the value) will slightly darken the image without affecting overall quality.
Sharpening: Used to correct "blurriness" in an image. Always use “Sharpen (Spatial).” Sharpening increases the “sharpness” of the edges within the image. There are two components to this filter – Mask size, and Factor.
The mask size should always be set as high as possible, with the factor as low as possible. This will allow for the image to be sharpened, without adding too much graininess. For example, a mask size of 15x15 with a factor of 10-20 will oftentimes produce a great image.
It should be noted sharpening will always cause some level of graininess, with graininess increasing with higher factor values.
Noise Removal: Used to reduce “noise” (i.e., static) in the image. “Fast noise removal” is most used.
Adaptive Normalization: Works somewhat similar to gamma filtering but is not as commonly used. This filter usually already exists within the post-capture filters if a device requires it, however some devices need the values to be adjusted. See “device specific settings” for these settings.
Contrast adjustment: Not often used but can be useful in niche cases. Increases or decreases overall contrast between dark and light areas in an image. A value higher than 0 will increase contrast, while a value lower than 0 will decrease contrast. Adjusting in increments of 5 or less is recommended, if even needed.
Brightness adjustment: Increases or decreases the overall brightness of an image. Always use gamma correction first. A value higher than 0 will increase brightness, while a value lower than 0 will decrease brightness. Adjusting in increments of 5 or less is recommended, if even needed.
Invert filter: changes white to black and black to white. If an image is coming out inverted during initial testing, add or remove this filter.
Flip and rotation filters: Corrects image orientation. Only use if ALL images taken with a specific device are incorrectly rotated or flipped. For example, if all panos come out upside-down, add a vertical flip filter to the post-capture filters for the extension used to invoke the pano. If all sensor images come out rotated 90 degrees clockwise, add a 90 degree counter clock-wise filter to that sensor’s extension to offset this.
Most other available filters are rarely or never used – the ones listed above should be the only ones needed based on what the office is looking for in their image quality.
Exposure Time
Sometimes, the exposure time on the office’s tube head needs to be raised or lowered. If exposure time is too high, the image will be overall too dark and show something called “burnout,” which causes low density areas to fade into the background. If the exposure time is too low, the image will be underexposed, causing the image to be too light and washed out. The chart below can be used as reference for recommended exposure times:
*Please keep in mind that, outside of what is in this chart, we are most likely not familiar with your specific tube-head and how to adjust the settings. If you need specific instructions for changing these settings, please reach out to the manufacturer.
How do I adjust and apply Post-Capture Filters?
To review image quality, the office needs to capture an image of someone’s teeth first and foremost. This is necessary due to tissue density differences between the tissue around the mouth and other parts of human anatomy. Taking an x-ray of a key or a finger WILL NOT give you a good representation of how an image will look when taken on a live patient. These steps are used when dealing with a sensor that does not have known device specific settings, or when the “default” settings are not producing an image the office likes. Performing these step should help reduce the number of x-rays needed on a live person.
- View the image in XVCapture and go to Image Enhancements, or double-click on the image
- Go to Enhance > Automatic Enhancements > Create New Enhancement (this enhancement will not actually be used, this is just to determine what filters to apply to the actual post-capture filters later on.)
- A window will open containing the image and filters to be applied
- To add a filter, go to Filter Options > Add new filter > choose the filter(s) you need, and set its values
- Once the filters you have added are producing an image you’re happy with, take note of the filters in place or screenshot them, then cancel to back out of this area and go back to the home screen of XVCapture
- Go to Advanced User Tools > Preferences > Imaging Extensions > Drop-down digital x-ray image capture > select the device extension being used to capture these images > Image Quality Settings > Modify Post Capture Filters
- A window will appear similar to the previous area you had been testing the filters in
- Apply the same filters you had applied earlier. If any default filters populate within the applied filters list, leave them be. If one of the default filters is a filter you had applied during testing in step 4, edit that filters value instead of adding a 2nd filter (for example, if you applied a gamma correction of 0.80 in step 4, and a default filter for gamma set to 0.80 already exists in the PCFs, change that gamma filter to 0.60 instead of adding a 2nd gamma filter)
- Capture a new image of someone’s teeth to verify the images now come out correctly
- Apply same settings to each workstation that uses the same brand of sensor (filter settings are per workstation
Device Specific Settings
Refer to https://apteryximaging.zendesk.com/hc/en-us/articles/4407881878043. Schick 33, Elite, and AE sensors will use driver level filtering that can be enabled in the hardware settings. The attached article shows how to enable these step by step. No post-capture filtering is typically needed.
Kodak/Carestream (RVG) Sensors:
Try the following post-capture filters first, then capture a new image to see if the quality is improved:
If these settings do not work well for the office, please submit a ticket to our support team to have them attempt to either adjust these settings further, or create an enhancement within XVWeb instead.
Kodak/Carestream Pano and Ceph units:
Under the Kodak Universal extension settings (Advanced User Tools > Preferences > Imaging Extensions > Drop-down digital x-ray image capture > Kodak Universal > Miscellaneous settings) try setting the execution method to ‘Simple Process.’ DicomConvertToFP.exe needs to be able to run during acquisition to produce the correct image.
Pans/Cephs appear with B&W bars or Very Light
Processings2D.dll and DICOMConvertFP.EXE missing from install folder. Solution: Download and run newest extension upgrader from Current Imaging Downloads (Carestream (Kodak) Universal 11.0.0.3, under https://apteryximaging.planetdds.com/hc/en-us/articles/4412758829595-Current-Imaging-Downloads)
Dark/blurry panoramic images
Follow the steps above first, then try adding adaptive normalize at 1%, 2%, and sharpening at 15x15 factor of 20 to the Post Capture Filters.
If contrast is too high, adjust adaptive normalize filter to %1, %1 or %2, %2.
NOTE: If the office also uses RVG sensors on the same workstation, or other Carestream devices, ensure the affected modalities is set to PX
These devices do not typically need post-capture filters added or adjusted. Instead, plug a sensor in and right click on the sensor icon in the system tray and select “Image Settings.” In this window, enable “Optimizer.” This applies driver level filtering to the images produced by these sensors. If the Optimizer option is greyed out, GXPicture needs to be modified to enable “other software – filters enabled.” If assistance with this is needed, please reach out to Kavo/Dexis. The Optimizer being toggled on works for most offices, but if additional filtering is needed, add post-capture filters after enabling this.
Remove all post-capture filters (Filter Options > Delete All Filters) and apply the following:
If using multiple Instrumentarium/Soredex/Kavo units on the same PC as the Optime, please submit a ticket to our support team as additional configuration will be needed to avoid these settings from applying to other units.
image quality issues with Jazz sensors should be referred directly to Jazz Imaging. Jazz sets up image quality filters on a driver level using the Control Center. They are also familiar with adding additional post-capture filters if need be.
Vatech sensors always use an “Image Processing Mode” instead of post-capture filters. These can be found by going to Advanced User Tools > Preferences > Imaging Extensions > Drop-down digital x-ray image capture > Vatech extension with the sensor plugged in. Vatech Classic sensors should use Processing mode IP301 or IP664, while HD sensors should use IP701 or IP704.
E2V sensors (Tuxedo A Series, Quickray, Dentiray 4, XDR, etc.):
E2V sensors almost always use the following settings, combined with a gamma correction of 0.80 in the post-capture filters:
The sharpening factor can be raised or lowered if the image is blurry or too sharp.
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