Title: Melanoma and skin cancers vs Image Processing
1Melanoma and skin cancers vs Image Processing
2Skin cancer and melanoma
- Skin cancer most common of all cancers
3- According to the latest statistics available from
the National Cancer Institute, skin cancer is the
most common of all cancers in the United states. - More than 1 million cases of skin cancer are
diagnosed in the US each year. - Whats shown here are some examples of skin
lesion images. - The four images shown on the left are various
form of skin lesions, cancerous or non-cancerous.
- The two on the right are a specific form of skin
cancer melanoma.
4What is Melanoma?
- A type of skin cancer that starts from
melanocytes - 6th leading cause of cancer death in the US
- No single etiology
- Some risk factors include
- Sun exposure -depleting ozone layer
- Presence of many or unusual moles
- Skin types
- Genetics predisposition
5benign
skin
malignant
6Skin cancer and melanoma
- Skin cancer most common of all cancers
Image courtesy of An Atlas of Surface
Microscopy of Pigmented Skin Lesions Dermoscopy
7Use of color to distinguish malignant and benign
tumors
- Skin tumors can be either malignant or benign
- Clinically difficult to differentiate the early
stage of malignant melanoma and benign tumors due
to the similarity in appearance - Proper identification and classification of
malignant melanoma is considered as the top
priority because of cost function - Classification of skin tumors using computer
imaging and pattern recognition - Previous texture feature algorithms successfully
differentiate the deadly melanoma and benign
tumor seborrhea kurtosis - Relative color feature algorithm is explored in
this research for differentiate melanoma and
benign tumors, dysplastic nevi and nevus - Successfully classify 86 of malignant melanoma
using relative color features, compared to the
clinical accuracy by dermatologists in detection
of melanoma of approximately 75
8Types of Melanoma
- Superficial Spreading Melanoma
- 70, neck, legs, pelvis
- Nodular Melanoma
- 15, dome-shaped nodule
- Acral-Lentiginous Melanoma
- 8 , Common in dark-skin
- Lentigo Maligna Melanoma
- 5 , sun-exposed area, mistaken for age spot
- Amelanotic Melanoma
- 0.3, non-pigmented
- Desmoplastic
- 1.7, ½ amelanotic
9Benign vs Malignant
9
1010
11Automated Melanoma Recognition UsingImaging
Techniques
- Melanoma is one of the most aggressive cancers,
but it can be healed by surgical excision
successfully only if it is recognized in the
early stage. - Since the melanoma emerges as a tiny dot in the
topmost skin layer, it can be examined during
routine medical check up. - Although the lesions are accessible, in many
cases, it is a difficult task to make decisions
whether nevi are benign or malignant. - Further, frequent use of biopsy is also not
encouraged. - Hence, to assist dermatologist's diagnosis, it is
useful to develop an automated imaging-based
melanoma recognition system.
12- Uncontrolled growth of melanocytes give rise to
dark and elevated appearance of melanoma. - Neoplasm- growth of tissue, tumor
- Melanoma is a type of malignant skin cancer that
starts from melanocytes. Its caused by
uncontrolled growth of melanocytes that gives
rise to tumor.
13- Nonetheless there are risks factors that highly
attributed to its incidence. Some of the them
are - amount of sun exposure the more cumulative
exposure the higher - presence of many of unusual mole people with
many moles in the body - Fitzpatricks Skin Type I and II have higher risk
1975 Thomas Fitzpatrick, Harvard skin typing
system based on skin complexion and response to
sun exposure - genetic predisposition if there history of
melanoma that runs in the family - According to a study ,compared to general
population, people who with 2 risk factors have
3.5 times risk of developing MM and 20 times
those who have 3 or more risk factors.
14- These are the types of melanona
- As you see, SSM is the most prevalent one that
makes up 70 of most diagnosed melanoma - In this work, images of superficial spreading
melanoma were only explored. - The reason being, and the problem that this work
is trying to solve, Dysplastic Nevi ( a benign
mole) has properties that are highly similar to
this SSM melanoma, which makes the diagnosis of
melanoma difficult.
15Melanoma Incidence
NCHS national center for health
statistics Bureau of Health Statistics
Incidence highest in Caucasian skin
Graph one- Caucasian has the highest incidence of
MM. Having fair complexion is one of the risk
factors. Researches attribute this to low level
of melanin that absorbs harmful UV radiation in
fair skin, thus UV penetrates much deeper layer
affects the surrounding cells.
16- Graph two men shows higher incidence than
women. - A study of in Germany linked this trend to
mutation of genes called BRAF 4 and CDKN2A 1.
17Melanoma Incidence
Graph thee Incidence increases with age. Link
to cumulative sun exposure Some studies
suggested that people who had significant
exposure to UV at younger age have higher risk in
later age when UV exposure decreases.
Incidence increases with age
18- Age-adjusted- distribution of age by percentage
- Its a way of data normalization so that you can
compare two different countries, cities and so
forth - Need standard population distribution
- Who use it
- NCHS national center for health statistics
- Bureau of Health Statistics
- What to say
- So these are three graphs that show melanoma
incidence in different dimensions based on race,
gender, and age. - Here, its evident that Melanoma has its
favorites, so to speak.
19Melanoma Incidence
It is estimated that 62,480 men and women (34,950
men and 27,530 women) will be diagnosed with and
8,420 men and women will die of melanoma of the
skin in 2008 (SEER)
20- Surveillance Epidemiology and End Results
- What to say
- This is the combination of all of the data from
the previous slides. - Average of 4.2 percent increase per year
21Survival Rate by Stage
The American Joint Committee on Cancer (AJCC) TNM
System
http//www.cancer.org
22- The imaging is performed by a special CCD camera
combined with an epiluminescence microscope in
order to produce digitalized ELM images of the
skin lesions. - Once the images are captured, the lesion has to
be segmented from the background and useful
information should be extracted from the lesion
region. - Based on the extracted features, decisions have
to be made about the nature of the skin lesion. - The decisions should be supported by descriptive
justifications so that dermatologist can
understand the decision making process.
23- Contact person Assoc. Prof. PonnuthuraiNagaratnam
Suganthan, email epnsugan_at_ntu.edu.sgTel
6790-5404 - Collaborators Prof. C L Goh, MD, National Skin
Centre, Singapore Dr. H Kittler, University of
Vienna - This is an on-going project. We have implemented
the segmentation, feature extraction and
clasifcation modules satisfactorily, although
further improvements are desirable. The module to
provide explanations supporting the classifcation
decisons is yet to be developed. siii
24Skin cancer and melanoma
- Skin cancer most common of all cancers
- Melanoma leading cause of mortality (75)
- Although represent only 4 percent of all skin
cancers in the US, melanoma is the leading cause
of mortality. - They account for more than 75 percent of all skin
cancer deaths.
Image courtesy of An Atlas of Surface
Microscopy of Pigmented Skin Lesions Dermoscopy
25Skin cancer and melanoma
- The time line shown here is the 10 year survival
rate of melanoma. - If caught in its early stage, as seen here,
melanoma can often be cured with a simple
excision, so the patient have a high chance to
recover. Hence, early detection of malignant
melanoma significantly reduces mortality.
- Skin cancer most common of all cancers
- Melanoma leading cause of mortality (75)
- Early detection significantly reduces mortality
Image courtesy of An Atlas of Surface
Microscopy of Pigmented Skin Lesions Dermoscopy
26Clinical View
Dermoscopy view
Image courtesy of An Atlas of Surface
Microscopy of Pigmented Skin Lesions Dermoscopy
27Dermoscopy
- Dermoscopy is a noninvasive imaging technique,
and it is just the right technique for this task. - It has been shown effective for early detection
of melanoma. - The procedure involves using an incident light
magnification system, i.e. a dermatoscope, to
examine skin lesions. - Often oil is applied at the skin-microscope
interface. - This allows the incident light to penetrate the
top layer of the skin tissue and reveal the
pigmented structures beyond what would be visible
by naked eyes.
28Dermoscopy
- Dermoscopy improves diagnostic accuracy by 30 in
the hands of trained physicians - May require as much as 5 year experience to have
the necessary training - Motivation for Computer-aided diagnosis (CAD) of
pigmented skin lesion from these dermoscopy
images.
29- In the future, with the development of new
algorithms and techniques, these computer
procedures may aid the dermatologists to bring
medical break through in early detection of
melanoma.
30- 40,000 people between 1988-2001
- Cancer stage is categorized into TNM level
- T tumor ( localized)
- N regional lymph-nodes
- M -Metastasis
- The key point is the earlier the better of
survival - 5- and 10- year survival mean percentage of
people who live at least 5 and 10 years
respectively after being diagnosed
31Diagnosis- ABCDE System
32- E evolution/elevation
- What to say
- ABCDE system is the tool for detecting melanoma.
This is a list of criteria that can be used for
distinguishing between benign and malignant
melanocytic skin lesions. - A- if you draw a line across the center of MM,
youll see that is not symmetric compared to
regular mole - B- the border is uneven or ragged is a sign of
melanoma - C-if there are multiple shades of pigment is
presence - D- diameter gt 6mm
- Dermatologist adds E for either evolution if
lesion changes upon observation or E for
elevation. - Suspicious lesion is followed by histological
confirmation.
33Where the problems lie
- Atypical nevi acquire several properties similar
to melanoma, their recognition posed high
difficulties even to experts. The classical ABCD
guidance is not reliable therefore cannot be used
as sole indicator for detection of melanoma for
both clinical and public examination. - In clinical setting, recognition and
discrimination are highly subjective with rate of
success based on experts years of experience. As
was found, inexperienced dermatologists showed
decrease sensitivity in the detection of melanoma
in both live and photo examinations. - General practitioner 62 sensitivity and 63
specificity - Dermatologist 80 sensitivity and 60
specificity
34- OK, so we have the ABCD diagnosis tool plus the
experts. - So anyone with sort of skin lesion can step in a
clinic get the ABCD tool and experts examination
undertaken then there you have the results. - You either have benign mole or malignant melanoma
at the end of the consultation. Everything just
goes as plan. - Unfortunately it is not always the case.
- Sensitivity TP/TPFN
- Specificity TN/TNFP
- Read the bullet
- The objective of the this work is to address
these problems
35MM and DN
Here you have some samples of MM on the top row
and DN on the bottom row Atypical Nevi (mole)
shares some sometimes all characteristics of
MM. This actually what makes melanoma detection
difficult.
Malignant Melanoma
Dysplastic Nevi
36Objectives
- To construct an automated, image-based system for
classification of Malignant Melanoma and
Dysplastic Nevi using solely the visual texture
information of the lesion. The system will be
based on methodologies that emanate and/or
correlated with human vision therefore will
closely emulates human experts only with greater
extent of accuracy, reliability and
reproducibility - Investigate new segmentation methods that will be
effective on both lesions - Extract most relevant texture information from
the image - Construct a classification system of the lesion
37- Ultimate goal is the construction of the
classification system - The uniqueness of the system is the fact that
- only texture information is used robust in
color variability - Methodologies used through out the whole process
emanate from the human vision thus emulate human
expert
38Systems, Materials and Tools
- Image database
- Original tumor images
- 512x512 24-bit color images digitized from 35mm
color photographic slides and photographs - 160 melanoma, 42 dysplastic, and 80 nevus skin
tumor images - Border images
- Binary images drawn manually and reviewed by the
dermatologist for accuracy - Software
- CVIPtools
- Computer vision and image processing tools
developed at our research lab - Partek
- Statistical analysis tools
39CVIPtools
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41Other approach - Texture
42System for Melanoma Detection
43Outline of the Process
- Here you have the outline of the process
- Each of the subsequent step is dependent of the
of the preceding steps. In other terms, the
results of subsequent step is only as good as the
results of preceding steps. - Therefore, since segmentation is the top most of
the hierarchy, its important to make sure the
method is robust.
44Hypotheses
- Due to observable pattern disruption in the skin
tissue driven by the MM, It is hypothesize that
measuring magnitude of pattern disruption
provides discriminative features for diagnosing
MM. - Since visual texture is highly length-scale
dependent, It is hypothesized that the detection
and analysis methods that explore texture at
different scales such as the wavelet is the most
appropriate approach. - It is hypothesized that texture descriptors that
emanate from and highly correlated with human
vision system provide the utmost representation,
and thus yield a more contextual systema system
that closely emulate human expert
45- Item one skin has distinct uniform pattern
(glyphic pattern). - MM disrupts texture.
- Quantifying texture differences between MM and NV
is more reliable method than color-based (
color-based in prone to variability in imaging
system) - Item two texture come in different sizes.
- Detection method that explore texture image at
different possible scale is more sensitive than
methods that are using one scale. - Example of this snake-based ( gradient-based),
Normalized Cut, histogram threshold -
46- Item three there are many texture descriptors
that are purely algorithmic that may not
necessary correlate with human vision. - One example is first-order statistics of texture
( variance ,mean), structure-based approach,
laplacain of Gaussian. - Texture classifiers that emanate from or highly
correlated with human visual system provides a
closer approximation of experts perception of
texture.
47Visual Texture
48Texture
Technical Definition
- Texture is regarded as what constitutes a
macroscopic region. Its structure is simply
attributed to the repetitive patterns in which
elements or primitives are arranged according to
a placement rule(Tamura et al, 1978). - Texture is both the number and types of its
(tonal) primitive and their spatial arrangement
(Haralick ,1979). - The term texture generally refers to repetition
of basic texture elements called texels. The
texel contains several pixels, whose placement
could be periodic, quasi-periodic, or random.
Natural textures are generally random, whereas
artificial textures are often deterministic or
periodic. Texture may be course, fine, smooth,
granulated, rippled, regular, irregular, or
linear (Jain, 1989). - Texture is intuitively viewed as descriptor in
providing a measure of properties such as
smoothness, coarseness, and regularity (Gonzales
and Woods, 1990). - Texture is an attribute representing the spatial
arrangement of the gray levels of the pixels in a
region (IEEE, 1990). - Texture is both grey level of a single pixel and
its surrounding pixels, which was coined as a
unit texture, texels. These texels conformed
repetitive patterns that dictated the effective
texture analysis approach (Karu et al, 1996). - Patterns which characterize objects are called
texture in image processing (Jähne, 2005).
49- Texture has no single definition.
- Definitions from previous literature dedicated in
studying texture - The first three definitions, tells us texture is
composed of a building block that is spatially
arranged based on the placement rule (periodic,
quasi periodic, or random) like a brick a single
brick is the building block, the arrangement of
the bricks that gives rise to a texture of a
brick wall - Texture is descriptors for smoothness,
coarseness, and regularity - In computer vision
- Spatial arrangement of gray levels of the pixel
- Pattern
50Texture and Human Vision System
- Pre-attentive visual system-1962-1981
- Dr. Julesz
- Neuroscientist
- Texture perception
- Statistical approach
- Disproved conjecture that second-order is
processed in the vision system - Textons
- Contrast
- Terminator-end of lines, corners
- Elongated blobs of different sizes - granularity
51- As one of the hypothesis. Texture
characterization emanate from visual system
closely emulates experts - Neuroscientist, studied perception of texture
- Before disproving, he conjectured that
second-order statistics is processed in the
vision system, and He claimed that two textures
with similar second-order statistic is not
pre-attentively recognizable. - In other words without close inspections, two
different texture with same sec stat would seem
to look similar. - After series of experiments, he finally suggested
that textons are the major player for texture
discrimination. - And the textons are contrast, terminators.
granularity
52Texture discrimination
Textons instead of second-order statistics that
cause the texture discrimination
Textons
Second-order statistics
53The image on left is an example of two different
textures with the same SO that is not
pre-attentively detectable.The right image is
two different textures with the same SO but
pre-attentively detectable. Among others this
leads to the final statement texture
discrimination is made possible through the
textons. Here in this one is the difference
termination of the two texture elements .In
this work, the second-order statistics CoM and
contrast of edge elements will be explored for
extracting visual texture properties of skin
lesion.
54Texture and Human Vision System
- Frequency and Orientation
- Multi-frequency and orientation analysis
- decomposition (1968) Campbell and Robson
- Simple cells of the visual cortex respond to
narrow ranges of frequency and orientation, cells
act as 2D spatial filter-(1982) De valois et al. - Orientation-based texture segregation involves
the generation of a neural representation of the
surface boundary whose strength is nearly
independent of the magnitude of orientation
contrast - Motoyoshi and Nishida (2001)
55- More studies had been conducted in part to
understand human vision. - This Campbell and Robson found that when signal
received by the eye is decomposed into multiple
frequencies and orientation - Another work in the subsequent year that further
support the previous finding that simple cells
are highly selective/tuned to narrow frequency
and orientation. - Another work found that neural representation of
texture boundary is formed that is independent of
magnitude and orientation of the contrast - In this work in wavelet analysis will be used for
segmentation. Frequency and contrast
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57Texture
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61Method Design
- Creation of relative color images
- Segmentation and morphological filtering
- Relative color feature extraction
- Design of tumor feature space and object feature
space - Establishing statistical models from relative
color features
62 63Create Relative Color Skin Tumor Images
- Purpose
- to equalize any variations caused by lighting,
photography/printing or digitization process - to equalize variations in normal skin color
between individuals - the human visual system works on a relative color
system - Algorithm
- Mask out non-skin part in the image to calculate
the normal skin color - Separate tumor from the image
- Remove the skin color from the tumor to get a
relative color skin tumor image - CVIPtools functions were used to create relative
color skin tumor images
64Calculate Skin Color
65Tumor Image
66Relative Color Tumor Image
67Segmentation and Morphological Filtering
- Image segmentation was used to find regions that
represent objects or meaningful parts of objects - Morphological filtering was used to reduce the
number of objects in the segmented image - Easy to use CVIPtools for experimenting and
analysis
68Feature Extraction
69Relative Color Feature Extraction
- Necessary to simplify the raw image data into
higher level, meaningful information - Feature vectors are a standard technique for
classifying objects, where each object is defined
by a set of attributes in a feature space. - Totally 17 color features and binary features
were extracted using CVIPtools - The three largest objects, based on the binary
feature area, were used in feature extraction - Histogram features, that is, color features, were
extracted in each color band from relative color
image objects
7017 Features
- Histogram features in R, G, B bands
- Mean
- Standard deviation
- Skewness
- Energy
- Entropy
- Binary features
- Area
- Thinness
7117 Features (Cont.)
72Design Two Feature Spaces
- Tumor feature space
- consists of 277 feature vectors correspond to 277
skin tumor images. - each feature vector has 51 feature elements,
which are the total of 17 features of each three
largest objects within the same tumor. - Object feature space
- had 842 feature vectors corresponding to 842
image objects - each feature vector has 17 feature elements,
which were the binary features and color features
stated as above
73Establishing Statistical Models
- Two feature spaces serve as two data models in
order to maximize the possibility of success - Two classification models, Discriminant Analysis
and Multi-layer Perceptron, were developed for
both data models - The training and test paradigm is used in
statistical analysis to report unbiased results
of a particular algorithm - due to small size of data set, 282 images, we
used the leave x out method, with both one and
ten for x - Partek software was used
- to analyze the data representing the features
- to develop a model or rules for classifying the
tumors
74Quadratic Discriminant Analysis
- A statistical pattern recognition technique based
on Bayesian theory, which classifies data based
on the distribution of measurement data into
predefined classes - Normalization the feature data as preprocessing
- performed to maximize the potential of the
features to separate classes and satisfy the
requirement of the modeling tool such as
Quadratic discriminant analysis for a Bayesian
distribution of the input data - Variable selection was used to choose dominant
features.
75Multi-Layer Perceptron
- A feed forward neural network
- neural networks modeled after the nervous system
in biological systems, based on the processing
element the neuron - widely used for pattern classification, since
they learn how to transform a given data into a
desired output. - Principal Component Analysis (PCA) as
preprocessing - a popular multivariate technique, is to reduce
dimensionality by extracting the smallest number
components that account for most of the variation
in the original multivariate data and to
summarize the data with little loss of
information - the dispersion matrix selected for PCA in this
project is correlation
76Multi-Layer Perceptron (Cont.)
- Creation, training and testing of neural
networks - Creation a neural network involves selection of
hidden and output neuron types and a random
number generation. - Four output neuron types Softmax, Gaussian,
Linear and sigmoid - Three hidden neuron types Sigmoid, Gaussian and
Linear - Scaled Conjugate Gradient algorithm is used for
learning in this project. - Automated and independent of user parameters
- Avoids time consuming
- Stopping criteria, sum-squared error, is selected
to determine after how many iterations the
training should be stopped - The trained data is then tested on itself first
to examine how far the neural network is able to
classify the objects correctly. - Leave x partition out method is used for testing
the algorithm
77Experiments and Analysis in Object Feature Space
- Discriminant Analysis
- 8, 9, 11 and 12 significant features were
selected respectively for leave one out method
Number of Histogram Features Area Mean Mean Mean STD STD STD Skewness Skewness Skewness Energy Energy Energy Entropy Entropy Entropy
Number of Histogram Features Area R G B R G B R G B R G B R G B
8 X X X X X X X X
9 X X X X X X X X X
11 X X X X X X X X X X X
12 X X X X X X X X X X X X
78Experiments and Analysis in Tumor Feature Space
- Discriminant Analysis
- 24 features selected for leave ten out method
Histogram Features Mean Mean Mean STD STD STD Skewness Skewness Skewness Energy Energy Energy Entropy Entropy Entropy
Histogram Features R G B R G B R G B R G B R G B
Object 1 X X X X X X X X
Object 2 X X X X X X X
Object 3 X X X X X X X X
- 10 features selected for leave one out method
Histogram Features Mean Mean Mean STD STD STD Skewness Skewness Skewness Energy Energy Energy Entropy Entropy Entropy
Histogram Features R G B R G B R G B R G B R G B
Object1 X X X
Object 2 X X X X
Object 3 X X X
79Experiments and Analysis in Tumor Feature Space
(Cont.)
- Discriminant Analysis (Cont.)
80Experiments and Analysis in Tumor Feature Space
(Cont.)
- Best features, being in the first three
components of the PCA projection data, were used - Success percentages of melanoma as high as 77
and nevus is as high as 68
81Experiments and Analysis in Object Feature Space
(Cont.)
- Discriminant Analysis (Cont.)
- Yield consistent results in classifying melanoma
from other skin tumor with above 80 success rate
82Experiments and Analysis inObject Feature Space
(Cont.)
- Multi-layer Perceptron (MLP)
- 5 out of 12 hidden-output layer neuron
combinations gave better classification results - Leave one out method
- Yield success percentage as high as 86 for
classifying melanoma. - MLP is more consistent in classifying melanoma as
well as nevus
83Conclusion
- Multi-Layer perceptron (MLP) with feature data
preprocessed by Principal Component Analysis
(PCA) gave better classification results for
melonoma than Discriminant Analysis (DA) - The best overall successful rate of 78, of which
percentage correct of melanoma is 86, nevus is
62 and dysplastic is 56. - The best classification results are achieved with
sigmoid used as the hidden and output layer
neuron type for the MLP with PCA on Object
Feature Space. - The three largest tumor objects are
representative for the whole skin tumor.
84Conclusion (Cont.)
- However the small percentage of melanoma
misclassification as well as the relatively low
success rate for nevus and dysplastic nevi
suggests that we may not have the complete data
set for the experiments. - In order to achieve better classification
results, future experiments - Needs more complete skin tumor image database.
- Should combine texture and color methods to get
better results - Will include dermoscopy images
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86Acknowledgement
- Dr. Scott E Umbaugh, SIUE
- Mr. Ragavendar Swamisai
- Ms. Subhashini K. Srinivasan
- Ms. Saritha Teegala
- Dr. William V. Stoecker, Dermatologist, UMR
87Thank You!
Yue (Iris) Cheng Graduate Student _at_ Computer
Vision and Image Processing Research
Lab Electrical and Computer Engineering
Department Southern Illinois University
Edwardsville E-mail cheng_at_westar.com https//www.
ee.siue.edu/CVIPtools
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89CLASSIFICATION OF MALIGNANT MELANOMA AND
DYSPLASTIC NEVI USING IMAGE ANALYSIS A VISUAL
TEXTURE APPROACH
University of Medicine and Dentistry of New
Jersey School of Health Related
Profession Biomedical Informatics March 2009
90Color-based Diagnosis Clinical Images
- Research Project Funded In Part by NIH
Yue (Iris) Cheng, Dr. Scott E Umbaugh _at_ Computer
Vision and Image Processing Research
Lab Electrical and Computer Engineering
Department Southern Illinois University
Edwardsville E-mail cheng_at_westar.com https//www.
ee.siue.edu/CVIPtools
91Spatially Constrained Segmentation of Dermoscopy
Images
- Howard Zhou1, Mei Chen2, Le Zou2, Richard Gass2,
- Laura Ferris3, Laura Drogowski3, James M. Rehg1
1School of Interactive Computing, Georgia
Tech 2Intel Research Pittsburgh 3Department of
Dermatology, University of Pittsburgh