Present Practice & Future of Compositing & 3D

                                                  By: Pulasthi Gunawardhana
                                                        University of Kent
                                                              May 2011


Putting an image onto the screen is an easy method in comprehending 3D. There is no horizontal offset and no distinction between the left and right eye, when the image on the scene gives the illusion of being where the theatre screen is. In real life for the projected scene to be one-dimensional, a flat wall or billboard poster would have to be used. If a real scene were filmed, all points would not fit on top of each other as points would in an ordinary scene. Shooting using two cameras would cause all of it to offset in a different way within the scene. A car far away appears slightly different for each eye, (inside the same shot) for someone close to the camera, the right and left would have a big differentiation. The whole image could be made to line up and overlap, if a poster on the wall were to be filmed; in addition, the poster would need to be observed by the audience as if it was in the same 3D space it appears in on the projection screen.

The 3D effect or „parallax‟ is relative to horizontal dislodgment, because of this if one of the eyes was shifted to the right or left, the image could be forced to shift in front from the back of the screen. If the image were shifted left or right, an opening would exist. The right and left frustum is like imagining the 3D world in movies, similar to having a viewing pyramid in each eye.

A scene filmed using parallel cameras produces a small piece one side not covered by both frustums. This same outcome occurs when the left eye is shifted to the side to increase the 3D effect.

In addition, a black strip would appear alongside one edge in 2D if a background plate were moved. There is not a black edge in 3D, but there is a section of the screen not containing information for both the right and left eyes. For example, the right eye might have some image, while the left eye does not. This could be removed by cropping, but this step is not necessary; the gap becomes nearly invisible in 3D projection. Furthermore, a large area of missing information at the frame edge of one eye seen when viewed without glasses is not visible when watching with glasses.


Colour Adjustment

The left eye has to go with the right eye in basic grade from the start. Generally, a beam splitter or a mirror will colour the image a bit, usually in shadow areas. Each eye needs to be balanced accurately, for the area of research that is used to supply automated tools that perfectly match the right and left eye.


Colour Grading

Both eyes can be graded once the eyes have been balanced. The colourist risks getting headaches if the systems do not automatically implement matching grade to each eye right away or if the project cannot be graded in stereo. Frequently, one eye is graded at a time, with grade applied on the top of the above-mentioned offset grade. In the Scratch program, for instance, a grade can be transferred from one eye to the other by a hot key; however, in stereo programs, this type of grade transfer is not feasible.


Stereo Adjustments

Matching right and left eyes vertically is the first adjustment. Even if the head tilted, the eyes always remain set in relation to each other, so vertical position has to be verified in every shot.
The on-set team can correctly pull convergence, but edits can still utilize altering, and occasionally scenes require re-converging, basically a horizontal change. Moreover, a shot itself might be technically ideal in terms of convergence, but might not cut well with the shot subsequent or preceding it. It is feasible for convergence to be tapered for easier editing and avoiding irritating convergence jumps.

Forcing audience members‟ eyes to move a great deal between near and far objects quickly is never desirable, for this reason, Tim Baier created a graph from a python script based on a database. The database is used by Baier to graphically follow shots throughout the edit. Distant and near objects in the scenes are shown in the graph. If they are jumping too much, he could alleviate eyestrain by transporting the objects closer to each other on each side of a slice and feathering the disparity of the divergence and convergence. This is based on the content of the subject point and scene where the audience is likely to be looking.


Effects in Stereo

In 3D, straightforward tasks such as paint and roto are more complicated than it is in 2D. The right and left eye roto have to match exactly. It is not feasible to simply copy and paste from one eye to the other; roto work requires close attention because the alteration in perspective is so fine in detabuil.


Creative Stereo Effects

The director could still score the convergence per shot for comic or dramatic effect, even when the technical problems are solved.


Light and Flares Plays

Two items that do not film well in stereo are light plays and lens flares. Because a lens flare is so positional-based, the simple reserved interoccular variation of 64mm could cause the flares to vary from one eye to the other.


Special Passes

The silver screen utilized in Real-D could create a ghosting highlight from one eye to the other that is read similar to a second offset limit; but Real-D continues to be extremely well liked and is gaining popularity. A “ghost-busting” pass is done for the Real–D version; this reduces the bright highlights of the primary eye from the secondary eye to resolve the problem. Even though this avoids the ghosting effect, the left eye gets left with odd dark hot spots. The untouched primary eye is used as the standard TV and DVD versions because of these hot spots, and reasons of minor softening from beam mirrors/splitters and stereoscopic adjustment.


3D Scanning

A number of consumer solutions are available for 3D object scanning (LASER/LIDAR) or (photogrammetric based) for making digital doubles, but all these lack one thing; the extraction of 3D Mesh and Textures of live actors or animals.


Compositing in 3D Space

Whereas there is not anything to stop 2D techniques from being used for 3D, composting at the accurate depth has to be given particular thought. When it is composited with 3D live action, 3D objects that have wrong stereo placement in the scene could possibly be created. For instance, even though a car in 3D could be composited so that the car projects as if it was in front of other on-screen objects, the illusion of a 3D car would not have to be behind those objects 3D space. With green screen layering, the result effect is the same. 3D stereo priority and layer priority have to be given particular attention.

Wise ways to track scenes with fixed-relationship cameras are having one track for the primary eye and offsetting the second camera based on the known interoccular distance and convergences, following the second camera. When convergence is unknown or if convergence is dynamic throughout the shot, dual stereo tracks are necessary for both eyes.


3D Compositing Techniques

The proposed techniques are:

a) 2D video and texture acquisition using chromakey or rotoscoping techniques;
b) Separate editing of each video layer with masks creation;
c) The use of an existing 3D modeling application, where the 2D video layered mapped textures are placed in a 3D virtual environment amid 3D models.
d) Seamless incorporation of 2D and 3D elements by camera match of the virtual camera;
e) Colour correction of the elements independently, using an external video editing application (the linked videos in the virtual environment are updated automatically when editing);
f) Export (rendering) producing either a stereo-pair for anaglyph projection, or a 2D + Depth format; and
g) Final editing in a conventional 2D editing application.




Stereoscopic Visual Effects Compositing

Stereo filmmaking, focusing mainly on documentaries and educational productions, was forgotten until its recent revival in Hollywood studios. The reason for this was the high production cost and inadequate delivery methods (Red-Cyan Anaglyphs). The use of IMAX dual projection systems in combination with comfortable polarizing glasses has made the stereo viewing experience more exciting. Today, stereo 3D content design focuses mostly in 3D animations, because the virtual nature of the genre makes it simple to create. Existing 2D video/film Visual Effects composting techniques have advanced considerably in the last ten years, but are still lacking in the 3D stereo production area, and are very costly, even for a Hollywood budget studio. With the introduction of 3DTV auto-stereoscopic and volumetric displays, the next sensible development step in entertainment is to address the need for suitable content creation techniques.


Free Viewpoint Video

Research has shown that the same abilities that are common in 3D computer graphics also are offered by Free Viewpoint Video (FVV). Interactive free navigation means that users could choose their viewing path inside a visual scene and their viewpoint. FVV applies to real world scenes captured on camera, as opposed to computer graphics programs. Multi-view video coding is explained as an important component for free viewpoint video systems and 3D, when done in combination with the related research done for the standardization of MPEG multi-view (MVC). In addition, FVV systems are the best input for future Volumetric displays systems.


Product Objectives

To generate and demonstrate innovative and creative techniques and methodologies, a final video composition in stereoscopic or 3DTV format (a multi-user lenticular lens auto-stereoscopic displays is required to demonstrate the effectives of the 2D+Depth format, therefore if none is accessible at the time of the showcase, a Red-Cyan Stereo Anaglyphic video with the suitable glasses will be presented instead)


Art of Roto (compositing)

Phoenix Editorial‟s Matt Silver has provided the background of Roto and an explanation of Roto elements.

Rotoscoping is the method of physically changing video or film footage frame by frame. To make custom animated effects like light-sabers or lightning, add paint randomly to it, or construct holdout mattes for compositing elements in a scene or frames could be traced to make realistic conventional animation. Visual effects and motion graphics are the two things generally made by VFX artists. If a detailed knowledge of rotoscoping and how it works into the modern digital pipeline is not utilized, then effects and designs are limited.

Rotoscoping is done very differently today, because digital tools like After Effects (AE), Combustion (C3), Digital Fusion (DF), Commotion, and Shake was introduced. When digital artists have detailed information about Rotoscoping, they are able to make improved incredible visual effects and live-action or CG composites. There are different Rotoscoping techniques: matte creation, digital cloning, paint touchup, effects painting, and motion tracking. These are covered below, including a short history of the craft.


Flint, Flame, Inferno, Fire, Smoke


The Advanced System, which includes Flint, Flame, Inferno, Fire, and Smoke, run on SGI workstations. Strong and high-spend Rotoscoping tools are a total post-production solution offered by these products. The painting and cloning tools are top-quality because of superior features, which includes brushed based warping and grand brushes. Even though Rotosplining is great, the inability to play spline over a moving image in real time and the lack of b-splines make Commotion better than Rotosplining. Roto work is offset to PCs and Macs that run Shake, Combustion, and Commotion, by facilities using Discreet advanced systems.


Digital Fusion

Today on NT/Windows desktop compositing solutions, Eyeon has one of the strongest positions, although in the past Alias 3D was used to provide a type of Fusion.

Digital Fusion has two chief products, Digital Fusion and DFX+.

Eyeon‟s ninth major release and flagship product was Digital Fusion 4. Eyeon‟s image processing software is Digital Fusion; the 8-bit flexible version is DFX+4. Superior character generation, flexible flow, and PSD importation to different layers for animation, are some of the important enhancements offered to DFX (DFX+‟s predecessor) by DFX+, which is based on the architecture of DF4. DF has provided cost effective solution, ever since Shake shifted away from NT/Windows.


Shake

For Quickshape, Quickpaint, Roto, and Rotoshape there are three options offered by Shake. Quickpaint is a procedural paint package within Shake. It is feasible to paint with interpolation or to paint frame by frame and then see it in real time. It is a sensible roto tool because every one of the paint elements could be animated over time. Today Rotoshape to a certain extent entirely overshadows Quickshape, an essential roto tool. Logical operations between roto shapes and variable edge gentleness are allowed by Rotoshape. Rotoshapes rotos, which are classic spline shapes, have velocity based on blur and difficult parent child relationships. Difficult rotoscoping are given especially precise results because of this. Shake has 2D trackers that can be used by Quickpaint and Rotoshape. Worthwhile to note that it is feasible to roto or paint throughout an image transform or track, even though Shake is a node workflow model.


Photoshop

Most likely the first digital rotoscoping tool used in film and video postproduction and the graphics application most widely used in the world is Photoshop. Although Photoshop could work by importing filmstrip files from video applications or with motion by importing frames one at a time, it was originally intended for still images. The target everyone else strives for is Photoshop‟s brush engine, and when used with pressure sensitive Wacom tablets it exercises great control. The lack of a real time preview of sequential frames is the leading drawback. Until clips are played back in real time at full resolution, the functionality level of the cloning cannot be determined.

In Photoshop after painting various frames, the sequence has to be taken back into compositing or editing applications, such as Final Cut Pro, to observe real time playback. Doing this makes a time-consuming method, and because video was not intended for it, it does not have moving matte capabilities and motion tracking.


Nuke

Nuke is the software which is currently using in the field for composting and VFX. It‟s a unique software which helps to create 3D VFX & stereoscopic task. This software got more than 200 nodes which is help to work more creatively and easily the task you do. Such as Rotoscopy, Keylight, Primatte, Vector blur, Multi color correction approaches, animated curve editor, multiple merge editor and vector paint tool are some of them which use full to do most tasks. Nuke got phythone scripting which help to user to customize the software as they need. Mostly user interface and control the process of the software. Using this software you can deliver simple pixel displacement to to 3D- macth move geometry.





Bibliography:
Content creation methods for stereoscopic / 3DTV Compositing in a 3D environment, and a multi-purpose Camera array acquisition system for multi-viewpoint video.
Pan. Vafeiadis

Compositing: Camera Matching
By: Allan McKay

Matting and Compositing of Transparent and Refractive Objects:
CHI-KEUNG TANG, MICHAEL S. BROWN, SAI-KIT YEUNG, and SING BING KANG.

NHS PACS System & Comparisson

NHS PACS System

And

Comparison

EPR 

 

Old System                                               

 New System

Introduction

PACS means Picture Archive Communication System. This is computerizes, network based diagnostic image & X-ray storage and also patient reports, distribution and retrieval system.

Managing workflow, organizing studies of patient diagnosis & presenting it clearly in hospital in done by using this system. Apparently for that, PACS system consists typically of an archive device, diagnostic viewing stations for radiologists and clinical review by physicians, servers to distribute the images via a public network and the required database and workflow management software. Digital X-ray modalities such as Computerized or Digital Radiography (CR/DR) are sometimes considered PACS components as well.

Before & After

Before PACS introduce to the world the scheduling time of the examinations used to be sorted out by their own. So then correctly ordered and patients get diagnosis. Then nurses prepare the patient for the examination while radiographer prepares to produce image production of patient’s diagnosis. Then the radiographer do the film processing from the machine which is contained the X-Rays films and fetches the diagnoses images.

After finishing the process of examination of the patient’s diagnoses film, it put to light board by radiographer to view the diagnoses.

After PACS introduce the radiographer take the images of the patient’s diagnoses and stored in the PACS. When the radiographer ready to view the X- Ray of a patient that patients X-Ray will appeared on the screen as image, when radiographer click the image of x-ray.

Before	After
Scheduling time of the examinations used to be sorted out by their own Radiographers have to take time to prepare for the examination Take longer time to do the examination.	No waiting list for the examination. No lost or misplace of images, because it’s place in the system. Better collaboration. Fast delivery of the & flexible to view

Advantages and disadvantages of PACS

Advantages	Disadvantages
Decrease in storage and filing costs Consistently high quality of images Examinations in order according to dates No chemical use for processing Rapid access to patient examinations An improved work area Deletion of images before closing case Elimination of film artefacts No lost films	Learning curve for software Transferring images from portable capture  unit Cost of technology maintenance Archive retrieval can be slow when demand is high

Golden rules of successful PACS

·      Avoid Making Mistakes

·      Network Infrastructure

·      Protocols Usage

·      Privacy and Security

·      Choice of Monitors

·      Choice of Archiving Servers

What are the benefits of sharing PACS information?

To make best care and deciding of the patients PACS images analyse by team of doctors and medical expertise. This is a benefits which will patients   get from PACS. These medical expertise and team of doctors known as “Multi Disciplinary Teams”, they will meet and discuss the diagnosis of a patients instance.

In some instances PACS information may need to be accessed by health professionals at different locations, for example if a patient is being transferred to a specialist hospital, and doctors need to see relevant prior images and reports.

According to the Lundberg report; the problematic in new system supported to cover the goal of a successful integrated and transformation of process. It’s bit complicated to find-out and cutting off the bad sectors comparing old and new working method.

Therefore many integration problems between the old systems work method and the new working method was evident some of the instances are,

·      The old system requires the A&E medical personnel to log off the system before attending a patient however this will not be accepted since in the current work pattern importance is given to the medical case where they do not have the time to log off systems as patients need immediate care.

·      According to the shortest list is on the old patient administration system, patients aren’t allowing find physicians.

·      The current system facilitates critical patient prioritising through the triage list while the new system facilitates this list by the use of the screen called “whiteboard” which does not provide any prioritising option.

Ways Radiographers influences with PACS

·      As PACS cut off the needs of repeating examinations via inaccurately taken images, this makes radiographers experience lower radiations.

·      Only once radiographers have to enter data to the system. This makes radiographers free from administration tasks and make freeing to keep attention on the certain patients.

·       As the lack of filming required PACS contribute to make chemical free environment in the wok place.

Way PACS affected to Hospital Consultants

·    Easy to accesses to patients diagnosis images

·    Reduce the amount of post-pone and wasted procedures, regarding not available of the patients diagnosis images.

·    Increase the consultations in between radiologist and the clinicians and this makes better collaboration too.

Number of way PACS change patients care

·    Lower Radiation dosage due to less retesting the patient

·    Quickly receive test results.

·    Treatments and discharging makes quicker than earlier and less wasting time with better care plane.

What is EPR?

An EPR is Electronic Patients Record system, which keeps record about a patient health in a computer. This will up to-date (past to present). EPR system is easier than keeping records in a file.

Changes of the Test results Distribution

Test results of the examination of a patient came to ward by mail, before introducing the EPR to the hospitals. There were two inboxes. One is normal inbox, which is for nurses in the hospital. Other one is abnormal for doctors (physicians). Then they discuss examination reports.

As EPR introduce to world. It makes work easier in the Hospitals. Patients test or examination results directly goes to patient’s folder in the EPR system. As soon as the certain physician read it he/she will delete it.

New Task introduced with EPR

Though the test results of a patients updating time to time in the EPR, some physicians wait until nurse came and discuss about the patient records, some physicians delete after they read reports of a patients without taking or looking further action for it. This makes work wired in the hospital.

The test results of a patient automatically flow to EPR system and this has challenge-seated routines, especially the nurse’s and physicians traditional pattern. Before EPR comes the results comes 3 o’ clock which is routines, but currently due to EPR system physicians or nurse can pop up patients records and result of test any time of the day as soon test finishes. So there is no harsh to waiting till results come to table.

Before EPR system nurses are used to discuss with the physicians after physician called them, and also sometimes nurses are unsure of that they could meet and discuss about test results or report with physicians in 3 o’clock or when physician call to them. But now its bit complicated, because its not finished. One goal of it should be improve effectively through exchange of information’s with the hospital staff, so this goal is a challenge.

Though the test results done twice from the electronic infrastructure, some test results not covering for daily ward work lot. This thing happening, because hospital staff paying more attention to serious results, and paying less attention in to less serious results, so less serious result not noticified by any until it comes to serious.

Reference:

Standards for patient confidential and PACS – Royal College of Radiologist

Impacts of PACS on Radiological Work – Nina Lundburg

 Subtle Redistribution of Work, Attention and Risks: Electronic Patient Records and Organizational Consequences -  Signe Vikkelsø

Assessment of PACS - Claudia Wild, Walter Peissl, Hilda Tellioglu

Singing cat pushing dog

Heart is crying without you.........

Though it's a short time I'm feeling so hard now without you.
Intentions and memories are visualizes in front me like a film strip.

It takes me far away instantly to ages to the dark and sweet past I spent once upon a time.
Love to stay and sleep hugging as much time as I could in her warm...
Even for ever like that till the death....

Endless stop-less feelings waking up me to take me there every single I breathe moment.
But patiently keenly waiting till rising up that day, with full of hopes in my heart and my mind, by counting days from 10 finger in my hand.

Counted not twice or trice, but several times.
Hours, days, weeks and months flying away without noticing.
But I'm waiting, with smiling face, crying heart like a kid to live with you in your warmth once again.

I hope that time is not so far, but it's not so closer.
Though you are so far, some day I will come to you with holding crown, world you made for me.


I L O V E Y O U A M M A



By: Pulasthi Gunawardhana