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What limits video resolution?

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curtis74

Automotive
Sep 28, 2007
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I am not an electronics person by any means, I'm an automotive engineer, but I wondered what is the current limit of video resolution and why? Is it the physical size of the pixel that limits us? Are there any emerging technologies that might make it much finer in the near future? I have an idea for a small video display with a very high resolution and wondered if its something I should pursue. If you folks could maybe enlighten me I would appreciate it since I'm (obviously) a little behind on these things.
 
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Lots of confluences:
wavelength of light
size of transistors
size of metallization
resistance of metallization
etc.

TTFN

FAQ731-376
 
Curtis, you're at a disadvantage if you don't know how a color television tube works. To start learning, look up 'electron gun' and 'shadow mask'. Got all that? Okay, forget it; it's old technology.

But LCD displays and such still have physical limits imposed on them, in analogous ways, all having to do with limiting the area of stuff that's excited, or individually addressing the sheer number of pixels that need to be switched, or just getting all the bits in a row on one wire, or three, or eight, and changing them and shifting them along the wire fast enough to maintain a decent frame rate, and... you probably have some reading to do.



Mike Halloran
Pembroke Pines, FL, USA
 
LOTS of reading, I'm sure.

I know how it works in general, including tubes and LCDs. You answered part of my question with the area of stuff to be excited. I was wondering if the resolution was limited by pixel size, and if so, what limits the size of the pixel?

Part of me is wondering if pixel size is limited by practical use or if we are currently at our highest resolutions based on the limits of technology... i.e. can we not currently make higher resolutions, or is it just that John Q. Monitorbuyer doesn't have a deep enough wallet to warrant making higher resolutions readily available on the market.
 
Why increase the res of a camera when there are no (or few) monitors that can display it? Why increase the res of a display when there are no cameras to take pictures with? Chicken and the egg situation, including standards that prevent 50 different types of non-compatible roosters trying to rule the roost.

Cost obviously plays a role, as who is going to buy a $100k TV on a teacher's salary? Unless you can get a lot of people to buy, it's costly to work out problems for newer technologies... why buy new technologies for $100k when you can wait two years and get them for $10k. Back to the Colonel Sander's routine again.

While the possibility exists for someone not skilled in electronics to come up with some revolutionary idea that the gEEks / physicists haven't thought of yet, but it's exceedingly unlikely as you're not even aware of the likely problems involved.

Your best bet is to throw us a bone, let us pick it apart for obvious gaping holes, and you can rest easier at night.

Dan - Owner
Footwell%20Animation%20Tiny.gif
 
I'm not coming up with the idea of higher resolution, I'm inventing a product that would benefit from it.

here's your bone. If you steal my idea I'm going to stab you with a plastic fork. :) Just kidding, I have the patent paperwork for it already. I just think it might be a big money maker for me and I don't want the idea getting around too much yet.

The idea I have is for a programmable hi-res display (in various sizes/lengths) for automotive gauges. Basically have a dedicated box into which you put all the sensor signals, then it outputs it to this display. The display of gauges itself would be almost infinitely customizable.

In a nutshell, its a display that could be available in several lengths/widths that you could mount in common classic and hotrod dash panels, then a box you could plug into your laptop (or a dedicated programmer) to customize the inputs, display, and orientation of the gauges.

The problem with using current resolutions is that things look really pixelated, especially when you're talking about a 3" guage simulation with 10pt font and a sweeping needle. In order to make it look decent, the resolution will need to be higher.

So, that was the origin of the question... what limits resolution? If its at its current best, then I need to hold off on the idea. If it can be improved but just hasn't been yet then I'm going to continue with the patent and research.

I agree that a teacher won't buy a $10k TV, and cameras don't need to be any higher res right now, but I DO think that a hotrodder will pay $1k for a snazzy gauge display for his street rod. The driver and hardware is the easy part. The only thing I don't know about is a higher res display.
 
Have you looked at any of the screens that are used in smart phones? They are ~3" and should have plenty of resolution(QVGA -> WVGA)....
 
The bad news for you is your idea is not patentable (at least in its current form)... there are already a ton of similar ideas out there already in production. I fail to see, however, how high-resolution has anything to do with your idea. Kopin has a sub-1" display with a resolution of 1280x1024, which should give you an idea of what's easily possible given current technology. Still, I think you're barking up the wrong tree.

Dan - Owner
Footwell%20Animation%20Tiny.gif
 
macgyvers, while I appreciate your commentary, your opinions on the product are not what I'm here to discuss. I'm simply seeking tech on resolution. It is the one aspect of this idea that I don't know about.

Play a racing game on your LCD monitor and take a look at the "gauges" on the screen. Their clarity is limited by the resolution of the monitor, especially with graphics that are at angles other than horizontal or vertical. If I'm going to market a product like this, it can't look like a series of square grains sweeping across the display. Higher resolution would help that, making the eye less likely to identify individual pixels at a glance.

Thanks all for the help on what I'm sure is a remedial topic for you folks, keep it coming.
 
Color screens are available in many physical sizes with aspect ratios of 4:3 or 16:9, for obvious reasons. If you want a different aspect ratio, your choices are more limited, and the markets are now small, so your costs will be higher. It might make economic sense to use multiple displays, say two or three, butted edge to edge, and it probably wouldn't hurt the ergonomics. Long horizontal analog gages have been tried many times, and nobody likes them.

As for pixellation, you might be able to reduce that by modulating the pixels along the line edges, so you trade off a jagged image and get a fuzzy one... or put a little dither in the needle image, so it looks like an analog gage that's fluttering a little. Computing power is so cheap today that you have a lot of options available in software.







Mike Halloran
Pembroke Pines, FL, USA
 
The gauges in a racing game are not typically limited by the resolution of the monitor. It's limited by having to do a bunch of intensive math in real time. They reduce the resolution so that they don't have to tax the processor so much.

I think the existing resolution is more than good enough your application. And Mike Halloran had a good suggestion with the modulation of the pixels on line edges. It's a very common technique.

Glenn
 
I think one can confuse level of detail (LOD) for a video game to the real world. Video gam LOD is ALL reserved for the scenery. Gauge verisimilitude just isn't that important.

As you can see from the Barco link, REAL LCD instrument displays are not lacking in resolution. The Kopin display is, or at least was, intended for a helmet mounted display, running serial color, i.e., 180-Hz single-color frame rate. For anything really dynamic, there will be a noticeable color bleed.

What's lacking for this application is horsepower, not resolution. To achieve the LOD required for a high-resolution display, you need a high-resolution graphics card, which is not what you find on a typical embedded graphics controller in a typical single-board computer.

TTFN

FAQ731-376
 
Ok... now we're getting into some real meat. Keep in mind that some of these terms I'm having to google to keep up, but I'm following :)

As far as monitor resolution versus software resolution, I'm hip to that. The "race software" to which I refer doesn't worry about processor load, it does its thing and all it is responsible for is sending a VGA signal to the monitor. Gauge resolution in a race game has nothing to do with processor speed, it has to do with what the software sends. I have just seen so many instances where resolution killed the deal. The first iterations of my idea were terrible, and they were limited by the resolution of the MONITOR, not the software. Every time the needle would sweep, it looked like you were dragging a drawn line in Photoshop; two lines one pixel apart. I can't have a line that (to the eye) looks like a jagged line that moves like low-res pixels moving across a screen.

Put it this way; no resolution I have ever seen has even come close to what I need, and one of the things I have a lot of experience with is using PDAs to program ECMs with WVGA-based sweep needles as part of the software. When I look at it, I see pixels, and lines drawn with square edges that jump with subtle changes in input.

The net result that I want is to be able to look at the display and have it not look like a bunch of square pixels. In order for this idea to be marketable as per my goals, it has to exceed what 90% of the public sees in their daily lives.
 
As others have said, it appears like you need to change your mind about what super resolution really offers you (or doesn't, in this case). I have standard-res displays that cost a few hundred dollars that you would swear were nearly photographic due to proper coding of the graphics (my master's research was in video/imaging).

Should that not dissuade you, let me try another tack... you mention a $1k value that a hotrodder might pay. Ignoring the actual engineering that would go into creating and programming such a system and looking at just the screen cost itself, you're $1k budget is gone before you eat breakfast. Even at high yearly quantities (10k+ units, which you might be lucky to reach 1k units/yr), a super-res screen the size of a gauge cluster is going to be several thousand $s. Technologically, what you're looking for is possible, but it's not feasible for the low dollar value you might bring to the display manufacturers. Sharp, Panasonic, whomever is simply not going to try stuffing that resolution into a screen so that they can manufacturer less than 100k units/year (and more likely 1M+ units/year).

Dan - Owner
Footwell%20Animation%20Tiny.gif
 
Again, you're confused. The resolution of the video sent to the graphics adapter is precisely limited by design and processor speed. You can get improvement if you can pass the processing load to the graphics processor, but that's because the graphics processor has tons of throughput for processing graphics.

In each example, you assume that the pixelation is display related, which it's not. The pixelation was BY DESIGN, either because there wasn't enough throughput, or the designer felt it unnecessary to provide better resolution.

Most displays are designed for viewing at distances exceeding 20 inches. At that viewing distance, the line pair resolution of the eye is about 2 pixels for a typical display. A program designed specifically for any given physical resolution can provide imagery you think you need. The pixels on a large screen TV are substantially larger than those of a 19" monitor, yet, no one complains about pixelation on those TVs.

I would second Dan's comments about costing. Removing pixelation is a complete luxury. Given the tradeoff between spending $1000 for a pretty display vs. an extra 100 hp, the usual choice will be for the latter.

TTFN

FAQ731-376
 
Can you tell us a little more about the prototypes you've already built and found unsatisfactory?
E.g.
Display resolution, display driver, graphics CPU type and speed, programming language, algorithms for line generation?



Mike Halloran
Pembroke Pines, FL, USA
 
No prototypes yet, just software that I can view on my monitor. At this point I have a programmer sending me some preliminary software that has everything I want. I'm able to simulate needle motion by grabbing sliders at this point which is simpler than simulating actual inputs. I'm running it on a more than adequate custom built PC with a 19" monitor, 1280x1024 digital video, 2g ram, 3.2g intel, all on an Asus mother, so the base hardware is up to the task. I'm trying to remember which Radeon video card I have, but it was the top of the line non-pro model last year, 512mb. And the software itself is only using a tiny bit of memory to run the simulation display, so I highly doubt that memory or throughput is the culprit. I've been able to tell him what I want and he has worked with Sony on the Xbox graphics, so as much as I would like to say he is the weak link, I doubt it. I'll try to get more details from him.

The problem is that I can clearly see pixelation and jerky movement as the "needles" pass from one pixel to the next. The video itself is exactly like I imagined and would be perfect if it weren't for the edges being so obviously made from little squares. Maybe I just have incredible vision and no one else can see it :)

For instance... this attached example (which is the little check mark below the compose pane) is ridiculously unacceptable for what I have in mind.
 
 http://files.engineering.com/getfile.aspx?folder=ef4026ab-e909-4ddb-8322-3ba000b03be1&file=checkmark.psd
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