How far is the automated 3-D segmentation of Brain MRI efficient compared to manual segmentation?

3d scanner body parts image

Sandhya

We are doing a project on automated 3-D segmentation of brain MRI using MATLAB. We would like to know the extent to which "Surf" commands are efficient in producing reliable segmented 3-D image. The accuracy level, how much it is better compared to manual segmentation. We need statistical detail, kindly help us....

Answer
This correspondence deals with the development of an
automated 3-D segmentation of Brain MRI. The proposal is a
model-based approach for accurate, robust, and automated
tissue segmentation of brain MRI data of single as well as
multiple magnetic resonance sequences. The main contribution
of this study is that we employ an edge-based geodesic active
contour for the segmentation task by integrating both image
edge geometry and voxel statistical homogeneity into a novel
hybrid geometricâstatistical feature to regularize contour
convergence and extract complex anatomical structures. We
validate the accuracy of the segmentation results on simulated
brain MRI scans of both single T1-weighted and multiple T1/
T2/PD-weighted sequences. When compared to a current stateof-
the-art region based level-set segmentation formulation,
our white matter and gray matter segmentation resulted in
significantly higher accuracy levels with a mean improvement
in Dice similarity indexes. Thus the development of the project
is done using MATLAB simulation for results.
A Hybrid Automated 3D Segmentation in Brain MRI -------------------------------------------------------- Advantages of a MRI scan
⢠MRI scanners are good at looking at the non-bony parts
or "soft tissues" of the body. In particular, the brain, spinal
cord and nerves are seen much more clearly with MRI
than with regular x-rays and CAT scans.
⢠Also, muscles, ligaments and tendons are seen quite well
so that MRI scans are commonly used to look at knees
and shoulders following injuries.
⢠A MRI scanner uses no x-rays or other radiation.
⢠A disadvantage of MRI is itâs higher cost compared to a
regular x-ray or CAT scan. Also, CAT scans are frequently
better at looking at the bones that MRI.

How are 2D cartoons animated today?

Captain Ca

I understand how 3D images are made, they generate models and send them through animations. However, how do they do 2D cartoons? I asume they don't draw each individual frame anymore. But, backgrounds that don't move do appear to be hand-drawn in some shows. How do 2D cartoons go through animations?

Answer
Depending on the budget, deadlines, technology, experience and preference that 2D animations are made one way or another.

Small budgeted shows, destined for the weekly TV slots are mostly done on Flash these days. Characters are created from simple shapes with movable body parts (mouths, hands etc.) are pasted onto individual layers and animated individually or in concert with the other parts.

The good thing about Flash is that you can position key drawings (important, story-telling character poses of say, a hand) out and the computer will fill in the in-between drawings (all the other drawings between the key drawings to smooth out the movements) automatically. So you can position the hand at one location (a key), and then program the computer to move it to another location (another key) and it will fill in all the in-between drawings by itself (timing is done by the animator). Computers are only good at moving objects around perfectly and stretching/squashing them according to preset rules so you are limited to certain expressions. Of course, complex scenes still need to be animated by hand, but to keep the cost and the time consumed down, animators don't get to do them frequently, if at all.

You can recognize these shows by the extremely smooth movements exhibited by the characters, as well as the bold and uniformed outlines and colors throughout. Backgrounds can be painted by hand, either digitally or on papers( and then scanned into the computer), or created from bodies of static shapes and colors.

Bigger, movie-length animated films use specialized softwares, either developed in-house, or bought commercially like the Toon Boom Animation program. These, however, are almost completely hand-drawn (characters-wise), since you can only create good character animation when you have a feel of the lines and forms of the characters, a thing that is quite difficult to program on a computer.

Some studios use papers and scanners, some use graphic tablets like the Wacoms to imput drawings into their computers. Some parts of a character can be animated while others are put on a different layer and remain static.

You can recognize these films by the slight jittery outlines of the character when he/she/it moves, since each line was drawn to match up with the previous drawings', though never perfectly so, no matter how hard the animators tried. The backgrounds are usually painted by hand (either digitally or manually on papers), or in 3D models that mimic a particular style or both.

Having said all that, yes, most animated shows are still drawn by hand. Some are done on papers and scanners, some are done on computers with Wacom tablets, some combine both in the production process. 2D animation is a craft, and unless computers can draw imaginatively, animators will still have their jobs, drawing them lovingly frame by frame. I hope that helped.

Powered by Yahoo! Answers

Title Post: How far is the automated 3-D segmentation of Brain MRI efficient compared to manual segmentation?
Rating: 100% based on 99998 ratings. 5 user reviews.
Author: Yukie

Thanks For Coming To My Blog