High speed, close, low latency
Editor’s note: This article comes from WeChat public account “ Quantum Bit “(ID: QbitAI), author thirteen.
This black technology makes AE effects come true in seconds.
Not long ago, a plugin called Lockdown from AE became popular: no matter how uneven you move, the pattern will fit seamlessly.
Actually, this magic special effect has come into reality.
This black technology is actually the projection we know. But unlike in the past, this time is a dynamic projection.
This high-speed projector is called DynaFlash.
The projected picture does not need to be flat. If the picture is distorted or blocked, the image can be completely printed.
If you want a better projection experience, the images you cast must be “fast, accurate, and cruel”.
It requires high frame rate and low latency.
This high-speed dynamic projector can project 8-bit images with a delay of 3ms, up to 1000 fps.
This topic has also become popular on Hacker News, with a heat of 1000+ points.
Many netizens exclaimed that the technology is “awesome”!!
I expect companies like Disney to be very interested in this technology.
I have been working in real-time projection for many years. Delay is the killer of this job. Any delay greater than 1000 / 90ms will have a special effect on the effect. This technology allows fast movement.
Cool Black Technology
How amazing is this black technology?
The image is projected onto a piece of paper. No matter how shake it is, the image will change synchronously with the deformation of the paper.
As if the image was pasted on paper.
In order to demonstrate the high frame rate and low latency of this technology, the research team also slowed down the video.
The dynamic projection under slow motion also achieves a perfect fit.
Of course, rotation doesn’t matter.
What’s more amazing is that the images can be switched freely with different projection screens!
What is it?
The black technology shown in the video actually uses infrared ink to draw marks on the target.
This mark is invisible to the human eye.
This is the Deformable Dot Cluster Marker (DDCM) proposed by researchers.
DDCM has three advantages:
1, even in the case of strong deformationIt can also be detected; 2. It can achieve robust tracking even when there is external or self-occlusion; 3. It allows millisecond-level calculation speed.
The following figure shows an example of DDCM.
△ An example of DDCM. Point clusters are distributed in an array structure.
DDCM consists of four types of point clusters, which are distributed in an array structure. As shown below.
Four types of delta point clusters. m represents the number of points. Each point cluster contains 1-4 points.
The points in each point cluster are topologically invariant, that is, they will not change under any deformation.
The number of
points is randomly and exclusively distributed. Recognition starts from the four corners of the p x p point cluster (recognition window).
In order to enhance the robustness of frame-by-frame tracking, the number of points in adjacent point clusters will not be the same.
△ No matter which corner is used to identify the window, there are no sequences that overlap each other.
The following figure shows the processing flow.
△ Processing flow
It consists of two steps: detection and tracking.
The detection process involves identifying the clusters of points from a single frame.
△ Detection process
The detection process is roughly as follows:
a) extract key points from the binarized image; b) consider the key points shown in a) located in the same grid and adjacent to each other as a cluster of points, red, green, blue, and yellow Representing m = 1, 2, 3, and 4 point clusters respectively; c) Calculating the Delauney triangulation of the extracted point clusters; d) Obtaining connectivity between point clusters based on breadth-first search; e) Finally, according to the pre-prepared The hash table identifies the ID of each point cluster according to the point number, and the red number indicates the ID of the identified point cluster.
The tracking process refers to independent, frame-by-frame tracking of each point cluster through an image sequence. It mainly includes the following processes:
a) Update the location of the tracked point cluster;
△ Update the tracked point cluster position according to ROI, which is indicated by a red square.
b) Track the recovery of lost point clusters;
△ DDCM-based array array structure tracking recovery.
c) False-positive tracking detection; d) interpolation of missing point clusters.
More ways to open
Think black technology can only do this?
The dynamic projection shown above only stays in the black and white color stage. The next way to open is even more cool.
With the countdown of “3, 2, 1”, the clothes suddenly appeared a dynamic projection with bright colors and complex textures. It is still you to pull, I am like a shadow.
Of course, there is a one-second drag wind operation.
The texture of the texture can also be changed, and with different actions and angles, the light and other factors will also change.
The naked eye 3D is no problem!
