Login/Register
Hint: separate multiple terms with commas
Date
E.g., 06/26/2019
Date
E.g., 06/26/2019
Feedback
Global
Global
China (简体中文)
Japan (日本語)
Korea (한국어)
Taiwan (繁體中文)
TI Training & Videos >
Applications & designs
Live training
Products
Tools & software
Toggle navigation
Hint: separate multiple terms with commas
Date
E.g., 06/26/2019
Date
E.g., 06/26/2019
Global
China (简体中文)
Japan (日本語)
Korea (한국어)
Taiwan (繁體中文)
Email
3.1 Advance features for existing SDK
For this session, we talk about how to have the advanced features existing SDK. So for this session, we talk about two major issues. First one is how to increase the pattern rate. Take 4,500 as a example. View step eight plus hybrid patterns, which means the total patterns need 40 patterns as I mentioned in previous slide. The maximum speed around 20 hertz. And later we talk about how to improve the pattern rate. Second issue-- when you do the scanning, we can find many lost scanning data like this one. This is this map. You can see many vertical and horizontal lines. Actually, it's lost data. So later we'll talk about what is the root cause and how to improve it. So about the pattern rate. So DLP4500-- the major issue actually is from the controller, DLPC350, because there's only 48-bit buffer in this controller, which means that you cannot load all the pattern in this 48-bit buffer. And also there's a few root cause plus one. Because of the [INAUDIBLE] always put in the first bit, so it means you put the first bit. But in the hybrid condition, the pattern always need to-- we use 8-bit [INAUDIBLE] pattern means the first bit would use only one bit. And the other seven bit is wasted. We only can use the left 42 bit. So there's waste some data here. And actually, we don't need this during the scanning, OK? Second one is when we do the-- if there's a pattern over 48 bit, means that we need to reload all the pattern from fresh. And from the fresh for the one buffer, it took hundreds of milliseconds. So which means when we display-- for example, we can use all the data for these three patterns. OK, when we display these three patterns and we load the buffer one from fresh during the display for these three patterns, and which means each pattern is-- it must run more than 43 milliseconds. Otherwise, it cannot load. There's not enough time to load the buffer one. If there is not enough time for the buffer one, you can see the pattern here is wrong. For correct one, it should look like this one. Should not mix the pattern with the previous one, OK? So the only solution is you must fit all the scanner data into the 48 bit. Otherwise, you cannot run with [INAUDIBLE] bit of DLPC350. And third, if you want to load all the data in 48 bits, you means it's very difficult for [INAUDIBLE] designed. The 40 patterns needs 82 bits. So the only way we deal with the size. How to reduce the size? First one-- if you use 8-bit [INAUDIBLE] pattern, actually there's a little waste. You only need six bits for most condition. So we can change the bit depth to six bits. We change it to six bits. You can actually increase the period for [INAUDIBLE] pattern. For example, actually we can use at 144 pixels for each period, for [INAUDIBLE] of a [INAUDIBLE] pattern. So we can generate more smooth [INAUDIBLE] patterns. And also these can reduce the pattern size. So for this condition, for example, for vertical and horizontal, we can use this setting plus this six-bit [INAUDIBLE] pattern. We can put all the scanning data to 48 bits. If we can fit all the scanning patterns in 48 bit, which means the DLPC350 can run the maximize speed, which is 400 hertz. OK, let's see some demo. Today we have three demos. First one is a standard SDK, which is 20 hertz pattern rate and a camera resolution along 1.2 megapixels. The second one is a standard SDK as well. The pattern rate is also 20 hertz. And then emitted by the DLPC350. And the camera resolution is much smaller. But [INAUDIBLE] limited by the DLPC350. So the pattern rate's still 20 hertz. So if we use the new code and use the smaller camera resolution, we can run at 180 hertz. And it's limited by the camera and the PC, OK. So we can run step seven. OK, stop scan. OK, so the capture time of [INAUDIBLE] condition is take a long-- 1.5 seconds. And the decode time is around one second and the total use-- 21 patterns. We can see the result here. OK, so it's a 1.2 megapixel resolution from the camera. So we can see this black area is due to a low reflectivity of an object, which is kind of a checkerboard. And we can see many dot pixels. And this is lost scanning data. So in the next section, we will talk about how to fix it. OK, then we can run step eight. OK, for step eight, the pattern number is 40. And [INAUDIBLE] on pattern one because pattern zero is [INAUDIBLE] pattern. So it waste the first pattern. And in the SDK, we also need to load all the patterns in the DLPC350. So the pattern capture time take a long 2.5 seconds. [INAUDIBLE]. We can see a step eight and step seven. Actually, [INAUDIBLE]. We still can see some vertical lines and some of the line over here. OK, so let's see the second demo. So for the second demo, because we only change the camera resolution, so we don't need to reload [INAUDIBLE], OK? We can start scan, by the way. So the same-- the capture also the same because it's limited by the DLPC350. You can see the scan result is not very good because the camera resolution is lower. So we can see the [INAUDIBLE] lines. It's very obvious. And also the reflectivity issue is very obvious. So for next demo, and we need-- we upload [INAUDIBLE] because we already changed the code and also with the pattern arrangement. So for the third demo, OK, we use faster camera speed. [INAUDIBLE] we use this new code. We're already finished download. Let's test the step eight first. OK, scan. OK, first, the pattern capture take a long 222 milliseconds. And the pattern, we only use 18 patterns, OK. So we can see [INAUDIBLE]. We have some [INAUDIBLE] lines and some reflectivity issue over here, OK. So for a new code, it's very obviously we can reduce a lot of scan time. And so we can run at maximum pattern rate.
Watch the next video in the series:
Advance features for existing SDK - Improve the lost point cloud
Details
Date:
June 6, 2018
In this presentation, it can give you why there is pattern speed limitation for DLP4500 and how to overcome it.
PDFs for download
dlp_3d_scannning_sdk_improvement-sec_3-1.pdf
Related courses and events
DLP660TE, DLPC4422, DLPA200 Chipset Overview and target display applications
Date:
April 27, 2017
How to Select the Resolution and Configuration for 3D Machine Vision Applications
Date:
July 21, 2016
System Design Considerations using DLP660TE, DLPC4422, DLPA100
Date:
April 27, 2017
Wearable displays with TI DLP Pico Technology
Date:
January 1, 2016
Smart Speaker Projection Techniques
Date:
January 24, 2019
arrow-top
close
delete
download
menu
search
sortingArrows
zoom-in
zoom-out
arrow-down
arrow-up
arrowCircle-left
arrowCircle-right
blockDiagram
calculator
calendar
chatBubble-double
chatBubble-person
chatBubble-single
checkmark-circle
chevron-down
chevron-left
chevron-right
chevron-up
chip
clipboard
close-circle
crossReference
dash
document-generic
document-pdfAcrobat
document-web
evaluationModule
globe
historyClock
info-circle
list
lock
mail
myTI
onlineDataSheet
person
phone
question-circle
referenceDesign
shoppingCart
star
tools
videos
warning
wiki