Motion Blur From a Video Microscope / Medical Display [Motion Blur Reduction]

[jamiew]

Forgive a newb who hasn't played many games since Quake 3 Arena came out.

I now spend my days looking down microscopes assessing tissue for diseases like cancer. There is a recent big shift to scan the tissue with slide scanners, and assess them on monitors: colour fidelity, depth and contrast, decent luminance etc are all important. When I am looking at tissue with the microscope, I assess the slide while it is on the move. My eye can cope with the movement and assess on the fly. The problem is you can't do the same with digital pathology assessing the digital slides when they are moving because of blur.

So the question is how do I get rid of this blur?

The digital pathology viewer is web based, streaming images on the fly from the local server. You don't see streaming issues. However, when you move the image to assess different parts of the slides, things blur including the fully resolved images already in the field of view. The standard monitor setup is a Dell UltraSharp 27" QHD U2715H - so yes, 60Hz. Trialing medical grade monitors, some looked better colour wise and luminance, but none dealt with the blur. A colleague who is still into gaming and thought he could see an improvement with a S3220DGF running at 164Hz and connected to discrete eGPU via Thunderbolt 3 (AMD RX 5700XT Ultra 8GB).

So the question - what in the chain is most likely to be causing this blur, how do I trouble shoot and resolve it?
Is it more likely a software issue? Do browsers have a refresh rate to consider?

From what I have read here and what I have seen in videos of games explaining the causes of blur, I think what I am seeing is ghosting. However there are also jitters with occasional lines coming across the screen. Amazingly this does not appear to be an issue the digipath system manufacturers appear to be aware of yet.

Then lastly, if refresh is likely to make a difference, and my priority is Brightness>No blur>colour depth>colour fidelity and I am looking at 27" - 32" monitors ideally at QHD what should I go for, and what laptop to run it? If I don't buy the kit that comes from the company, which suffers all the above problems, I would have up to £650 per monitor and up to £1800 per laptop (has to be portable for workers). NB The laptop that comes from the company is an Intel i5-8365U with 8GB ram, integrate graphics!

I probably explained myself really badly, but any help appreciated!!

[Chief Blur Buster]

Topic moved to motion blur reduction, but keeping link in General so others can see your thread.
Topic renamed to Motion Blur From a Video Microscope / Medical Display as it is not only the display alone.

So the question - what in the chain is most likely to be causing this blur, how do I trouble shoot and resolve it?
Is it more likely a software issue? Do browsers have a refresh rate to consider?

Being cited in over 20 peer reviewed research papers, let me see if I can help you:

There are multiple blur bottlenecks. It's almost definitely not your browser, unless the browser is lowering the frame rate of your video. First, wipe your mind of any preception that it is a browser fault, and switch to school/education mode when reading this forum post:

The most important thing is that Motion blur is frame visibility time.

The Motion Blur Weak Links

But there are many weak scientific weal inks on motion blur:
1. You have camera based motion blur.
2. You have display based motion blur.
3. You have framerate based motion blur.

You can incrementally address these one by one, and things improve.
1. Faster camera shutter will reduce source-based blur. How long is the camera exposure per frame?
2. There are two ways to reduce display motion blur:
...2a. Doubling the refresh rate can halve motion blur, but only if you can double framerate. Like this animation: www.testufo.com
...2b. Impulsing like a CRT can reduce motion blur. Lke this animation: www.testufo.com/blackframes
3. If you're on a sample-and-hold display (non-CRT), doubling frame rate can halve motion blur (yup, related to item 2b item). So raise camera frame rate, and make sure display has enough refresh rate to accomodate frame rate.

Examples:
60fps video with 1/1000sec camera shutter per frame, maxing-out the clarity possible of your 60Hz display. And if you want to improve things even further, then a 60Hz flicker display like CRT, plasma, LG CX OLED BFI, strobe-backlight LCD (Motion Blur Reduction backlight))

You need all the following.
(A) Short camera shutter time per video frame
(B) Short frame visibility time (e.g. ultrahigh framerate or a strobed framerate like CRT/plasma/blur reduced display)
(C) High frame rate (flickerfree display) or framerate matching Hz (flicker/impulsed display)

Motion Blur Mathematics

Blur Buster's Law means 1ms of frame visibility time translates to 1 pixel of motion blur per 1000 pixels/sec. But here's a catch when it comes to video cameras:

Source Based Motion Blur And Display Motion Blur is Additive

Example 1:
- 10 frames per second with 1/15sec camera shutter per frame
- Displayed on a fast 0ms GtG sample-and-hold display = means 10fps creates another 1/10sec display motion blur
- Blur Math: 1/15sec (shutter) + 1/10sec (display persistence)
- Grand total: 1/6sec total motion blur (excluding GtG!)
- 1/6sec = 167 pixel of blurring at 1000 pixels/sec panning speed
- OOOOOOUCH!

Example 2:
- 60 frames per second with 1/60sec camera shutter per frame
- Dislayed on a fast 0ms GtG sample-and-hold display = means 60fps creates another 1/60sec display motion blur
- Blur Math: 1/60sec camera shutter motion blur + 1/60sec display motion blur from persistence
- Grand total: 1/30sec total motion blur. (Add more if slow GtG display, since slow pixel response is additional blur)
- 1/30sec = 33 pixel of blurring at 1000 pixels/sec panning speed
- Okay compromise for lots of people, especially if you just have a common 60Hz LCD.

Example 3:
- 60 frames per second with 1/1000sec camera shutter per frame
- Displayed on a impulse-driven display that flashes the image for only 1ms (like a CRT) = 1/1000sec display persistence
- Blur Math: 1/1000sec (shutter) + 1/1000sec (display persistence)
- Grand total: 1/500sec total motion blur
- 1/500sec = 2 pixels of blurring at 1000 pixels/sec panning speed
- YAY! (except it flickers bad like a 60Hz CRT)

Is it possible your medical equipment resembles Example 1? Is there any way to improve it closer to, maybe Example 2 (even if Example 3 is impossible)?

(Anyway, in the ultra-long term, that's why I'm a big fan of Ultra HFR: Real Time 1000fps on Real Time 1000Hz, to eliminate motion blur without flickering like a CRT)

Educational Motion Blur Physics Animations

If too hurried to click on links, AT LEAST play these animations below to educate yourself on motion blur physics:

TestUFO ANIMATION: Motion Blur From Low Frame Rates

The lower the framerate, the more motion blur (until edges visibly flicker/stutter, like a slow guitar string). The higher the frame rate, the less motion blur. Retina frame rates is not until when framerates mimic analog motion (>1000fps at >1000Hz).

Click the links below:

TestUFO ANIMATION: Motion Blur Reduction From Strobing

This animation is limited in its ability to motion blur reduce to less than 1/60sec, but the above successfully demonstrates 20fps with only 1/60sec motion blur via black frame insertion (2 black frames 1 visible frame). This is the principle of flicker-based motion blur reduction such as CRT, plasma, BFI, strobing, etc. But strobing is a band-aid for low frame rates, since real life doesn't flicker, and the only way to emulate real life is analog-like frame rates (ultrahigh framerates at ultra high Hz)

TestUFO ANIMATION: Motion Blur From Sample-And-Hold Effect

The faster the motion, the more stutters blend into motion blur.
Then you're bottlenecked by refresh rate (need to double Hz and frame rate to halve motion blur)

Possible Fixes Within Your Means

1. VIDEO: What's the camera shutter speed? Can it be made faster? Faster shutter can also degrade quality (e.g. noisy images), twice as fast will halve camera-vs-subject-movement motion blur (including scenery movements such as microscope slide movements).

2. VIDEO: What's the camera frame rate? Can it be made faster. Faster frame rate reduces motion blur. From 10fps to 20fps to 30fps to 60fps. Higher frame rates have less motion blur; doubling frame rate will halve halve camera-vs-subject-movement motion blur (including scenery movements such as microscope slide movements).

3. PHOTO: Are you just panning a stationary photograph or stationary frame? (Basically microscope takes one picture, and you're panning the resulting picture?)

If so, you can fix this with a strobed display and/or high-Hz display such as a ViewSonic XG270 or XG2431 with PureXP=ON. All common browsers can scroll/pan at 240fps (FireFox, Chrome, Edge), which can reduce panning/scrolling motion blur. Don't forget to get a colorimeter to re-calibrate the display to your medical color standard (even a $200 Spyder or i1 will do fine). Be warned, strobing won't fully fix low-camera-framerates (e.g. 10 frames per second), but the duplicate-effect image of framerate-below-Hz (like CRT 30fps-at-60Hz or LightBoost 60fps-at-120Hz) may be more tolerable than a smeary display motion blur.

For flickerless sample and hold photo method (excludes video camera shutter/framerate blur):
120fps 120Hz has half browser scrolling/panning motion blur of 60fps 60Hz
240fps 240Hz has quarter browser scrolling/panning motion blur of 60fps 60Hz

For flicker/impulsed displays photo method (excludes video camera shutter/framerate blur):
1ms MPRT (not GtG) strobe backlight has ~1/16.7th = 94% less scrolling/panninng motion blur of 60fps 60Hz (1/60sec = 16.7ms)
1ms MPRT (not GtG) strobe backlight has ~1/8.3th 88% less scrolling/panninng motion blur of 120fps 120Hz (1/120sec = 8.3ms)

Ask yourself:
- Do you need motion blur reduction on video itself, or just motion blur reduction on panning individual photographs?
- How much motion blur reduction do you need?
- Do you prefer a flickerless or flicker-based motion blur reduction method?

More Reading about Display Motion Blur Physics

To understand better about motion blur physics, check out the Blur Busters education at www.blurbusters.com/area51 especially the educational display motion blur science/physics article, Blur Busters Law: The Amazing Journey To Future 1000 Hz Displays.

<shameless plug> Consulting! </shameless plug>
If you're selecting displays (or designing displays / cameras), and are looking for services from our business -- I may be able to give more personalized advice and/or even help assist in the design of specific displays to help address at least a portion of your blur weak links. Contact services.blurbusters.com

[jamiew]

3. PHOTO: Are you just panning a stationary photograph or stationary frame? (Basically microscope takes one picture, and you're panning the resulting picture?)

If so, you can fix this with a strobed display and/or high-Hz display such as a ViewSonic XG270 or XG2431 with PureXP=ON. All common browsers can scroll/pan at 240fps (FireFox, Chrome, Edge), which can reduce panning/scrolling motion blur. Don't forget to get a colorimeter to re-calibrate the display to your medical color standard (even a $200 Spyder or i1 will do fine). Be warned, strobing won't fully fix low-camera-framerates (e.g. 10 frames per second), but the duplicate-effect image of framerate-below-Hz (like CRT 30fps-at-60Hz or LightBoost 60fps-at-120Hz) may be more tolerable than a smeary display motion blur.

For flickerless sample and hold photo method (excludes video camera shutter/framerate blur):
120fps 120Hz has half browser scrolling/panning motion blur of 60fps 60Hz
240fps 240Hz has quarter browser scrolling/panning motion blur of 60fps 60Hz

For flicker/impulsed displays photo method (excludes video camera shutter/framerate blur):
1ms MPRT (not GtG) strobe backlight has ~1/16.7th = 94% less scrolling/panninng motion blur of 60fps 60Hz (1/60sec = 16.7ms)
1ms MPRT (not GtG) strobe backlight has ~1/8.3th 88% less scrolling/panninng motion blur of 120fps 120Hz (1/120sec = 8.3ms)

Ask yourself:
- Do you need motion blur reduction on video itself, or just motion blur reduction on panning individual photographs?
- How much motion blur reduction do you need?
- Do you prefer a flickerless or flicker-based motion blur reduction method?

More Reading about Display Motion Blur Physics

To understand better about motion blur physics, check out the Blur Busters education at www.blurbusters.com/area51 especially the educational display motion blur science/physics article, Blur Busters Law: The Amazing Journey To Future 1000 Hz Displays[/url].

<shameless plug> Consulting! </shameless plug>
If you're selecting displays (or designing displays / cameras), and are looking for services from our business -- I may be able to give more personalized advice and/or even help assist in the design of specific displays to help address at least a portion of your blur weak links. Contact

Wow. Many thanks for all this information. I am at work and will digest more when I get home tongiht, but your number 3 above is the situation. Basically a scanner uses high end objectives to systematically capture multiple images until all the slide has been captured at the necessary magnification and these images are then processed by the scanning computer to stitch them seemlessly together to create a single uniform image (whole slide image) that can later be launched in a browser based viewer. So its a scanner rather than a microscope, but your 3 is correct, it is producing a single static, not live image, for later assessment. Sometimes this is just at 400x mag, sometimes at 200x and 400x. These are then used to produce a layered slide image format that facilitates viewing at the desired maginification, which is anything from 1x through to 400x. A single static digital whole slide image would be typically be between 1 and 4Gb.

So the issue isn't at the capturing end because there is no live capturing going on, but in how the image is viewed. At the magnification you might assess the slide (e.g. 100x) you will only be looking at a fraction of the whole digital slide. You will then have to manually move and assess the image in x and y axes to assess the whole slide. This is where the problem arises, when moving the digital slide image in x and y, you have to: move, stop, assess, move, stop, assess, move, stop, assess, etc. Whereas, if you could sufficiently improve the motion blur, you could continually assess on the fly, improving the time to assess the whole digital slide significantly. Does this make sense? I'll try and take a video to demonstrate.

[jamiew]

i tried to post a video of an EIZO screen at 60Hz, the screen filmed with a mobile at 120fps, reduced to 30fps which makes the blur very clear, but I see you don't accept the links.

[Chief Blur Buster]

but I see you don't accept the links.

That's only the system's spam filtering for newbies (for the new users' first and second posts). Just post without the "http" and periods in the name. Once you have a few posts the system will let you post links.

i tried to post a video of an EIZO screen at 60Hz, the screen filmed with a mobile at 120fps, reduced to 30fps which makes the blur very clear

Video file is not directly useful for me for blur context (for certain scientific reasons: stationary eye = stationary camera, versus tracking eye = tracking/pursuit camera), but it may be useful to "count unique frames per second" to determine if your browser app is running the image-panning at a lower frame rate than refresh rate.

The other information you gave me is much more useful. So what you're telling me is you're panning / dragging around a static photo.

The good news is that for this use case, a higher refresh rate is an easy way to fix panning/scrolling motion blur, assuming your browser app is letting you drag the image at full frame rate/refresh rate. Most browser scrolling/panning is at full refresh rate (Google Maps panning reduces motion blur successfully), but if your medical app is a JavaScript-powered image renderer, it framerate may decrease. Is the medical app public or is it a private/proprietary website? Do you have ability to use an alternative image viewer to pan/scroll the image?

Are you able to determine if your panning-around is at full 60 frames per second? If so, there is high likelihood that (A) a higher refresh rate and/or (B) a strobe backlight, will solve your problem.

At framerate=Hz:
120Hz = ~1/2th motion blur
240Hz = ~1/4th the motion blur
Strobed = ~1/10th the motion blur

You might find a ViewSonic XG270 (240Hz panel with optional strobe-based motion blur reduction) configured to 120Hz PureXP+ useful for your specific situation (since refresh rate headroom improves strobe-based motion blur reduction for LCDs) -- unless you need a higher resolution than 1080p.

[jamiew]

Thanks again. This is quite reassuring. For what it is worth, here is the video.
https://1drv.ms/v/s!AhduGf_MljsfgbBMIetOmeaEN7eHcQ

[Chief Blur Buster]

Thanks again. This is quite reassuring. For what it is worth, here is the video.
https://1drv.ms/v/s!AhduGf_MljsfgbBMIetOmeaEN7eHcQ

Hello. Unfortunately the video file is hard for me to scientifically analyze without specifications for the video file because the video file is missing the variables to me (like missing EXIF data for video file)

1. Adjust video recording of your smartphone to quarter a refresh cycle or LESS (1/240sec camera shutter of faster for 60Hz), to prevent camera-blur-interference to analyzing your video. Or use 240fps high speed video (that guarantees 1/240sec exposure or less per vide oframe)

2. If possible, put application in windowed mode, and put www.testufo.com/flicker side-by-side with it. This gives me a refresh cycle counter reference, as well as a pixel-response speed reference for the specific LCD you're videoing at high speeds.

3. Question: Are you able to download the captured medical photo and pan locally in Windows Photo? Please try that and let me know if it looks any different (if it looks better, than you've got a programming performance issue in the browser software that pans the images. If so, it wasn't even maxing out the capabilities of 60fps 60Hz).

Also, don't discount possible GPU performance issues -- if you have an Intel GPU and a 4K display, then that may be a problem too. Upgrade your computer with a higher-end Intel GPU, or a low-end NVIDIA/AMD GPU, then panning will become higher frame rate in both browser and photo viewer.

In other words, you want panning blur to be similar to panning blur of dragging around Google Maps on a fast GPU. If your system has worse blur, then your browser app has a programming/efficiency bug or your GPU is underperforming. Anything that prevents framerate=refreshrate cannot be easily blur-optimized. In other words, 20fps panning has 3x more motion blur than 60fps panning, and 30fps panning has 2x more motion blur than 60fps panning.

Confirming full framerate panning is the critical answer I require properly confirmed, panning framerate=refreshrate, in order to confirm a guarantee of prescription of using a strobed gaming LCD. If there is an issue, then somebody needs to fix the JavaScript bug, or simply download the medical image from the browser and pan it locally using a local photo viewer like Windows Photo that will properly look fine blur-reduced at framerate=refreshraste. Confirming that a specific application pans a photo at 60fps at 60Hz is usually a good predictor that it will pan at 165fps at 165Hz or 240fps at 240Hz.

[Chief Blur Buster]

I looked at the filename of your linked file -- 120fps high speed video. Making rough assumptions of 1/120sec shutter 120fps HFR (of your video), if those variables are correct (which makes analysis possible). Analysis is much easier with a briefer camera shutter per frame, but I was able to determine:

(A) You don't have source based motion blur (GOOD)
(B) You seem to be running at framerate=Hz (GOOD)
(C) Your panning motion blur will be fixable simply by choosing a high-Hz monitor and/or strobed monitor (GOOD)

So that answers my question sufficiently. When a browser app does framerate=Hz (60fps), it usually scales properly at higher Hz. Also, a gaming mouse will help too. 125 Hz mouse will have stutter artifacts during dragging, so please upgrade your mouse at the same time too.

So based on my analysis, these upgrades will solve your motion blur problem during panning.

1. Any cheap 1000Hz gaming mouse (to makeddrag/panning smooth). For medical purposes, most gaming mice will be a panning-smoothness upgrade. You need Hz of mouse approximately 4x to 6x higher than display Hz, to avoid visible mouse microstuttering.

2. Cherrypicked high-Hz monitor with optional motion blur reduction mode.
If you are okay with 1080p 24" or 27" then I suggest a recently manufactured 240Hz "1ms" IPS gaming monitor (with a release date of 2020 or newer) with a well-reviewed strobe feature:
...240Hz nonstrobed = 75% panning/scrolling blur reduction
...120Hz strobed = 90-95% panning/scrolling blur reduction
So you have both options in the same monitor! That way you can try it both ways and go with what you prefer.

If you need a bigger and higher resolution display (48" 55" 65") then I recommend the LG CX 4K OLED HDTV or newer -- running at 120Hz with its "Black Frame Insertion" set to ON (maximum). The OLED will reduce motion blur by approximately 75%. Not as much as the best Blur Busters Approved monitor, but you get 4K and a massive screen size that can cover 4x as much ground (like a matrix of 4 computer monitors).

I must admit I'm partial to Blur Busters Approved monitors (since I helped the manufacturer fix motion blur better on these), run at large amount of refresh rate headroom to eliminate strobe crosstalk -- i.e. 120Hz strobe mode on a 240Hz-capable panel.

Do you need wide color gamut or are you okay with NTSC color gamut? Some medical work benefits from wide color gamuts, but there's the known red phosphor ghosting issue from certain KSF phosphors.

It will be a LOT more pleasant panning through microscope slides.

Optionally, if you wish to support Blur Busters, you can purchase these displays via these Amazon Affiliate links, which gives a small ~2.5% Amazon commission to Blur Busters for anything you add to the shopping cart via these links. You can reward our advice this way. And as most know, Amazon has good money-back return guarantees, if these end up inappropriate for medical purposes.

• Main amazon.com website link
  (Anything added to amazon.com through this link will commission to Blur Busters)
• 27" ViewSonic XG270
  (1920x1080p 240Hz + Blur Busters Approved strobe via backlight, among the better strobed 120Hz IPS currently available)
• 27" ViewSonic XG270Q
  (2560x1440p 165Hz + wide color gamut. Strobing not as good but colors MUCH more contrasty)
• 27" LG 27GL850
  (2560x1440p 165Hz + wide color gamut. No strobing, but same good non-strobed colors)
• LG CX OLED HDTV
  (4K 120Hz + optional blur-reduce strobe via BFI. Any of these sizes will do, all 2020 and newer LG OLED HDTVs have the BFI feature with 75% less blur than 60Hz LCDs. 4K resolution, OLED color, equivalent to 4 computer monitors, and much less blur = easier to identify problems quicker)

If you do 4K, make sure your GPU is fast enough to pan at 240 frames per second at 4K. I have seen thousands of displays as part of my Blur Busters career. If you decide not to buy via these links, make sure you avoid VA panels (most curved displays) or pre-2020-era IPS panels. High-Hz with good color looks best on modern FastIPS panels manufactured 2020 or newer. The GtG pixel response time needs to be a tiny fraction of a refresh cycle.