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Leveraging Social Media with Computer Vision
TJ Torres Data Scientist, Stitch Fix
Big Data Applications in Fashion MeetUp 10/2016
Informing Recommendations in Fashion and Retail
MOTIVATION
Inventory Scaling:
Why Recommendations?
Infeasible from an efficiency perspective to look through all inventory as it scales.
MOTIVATION
Inventory Scaling:
Human Ability:
Why Recommendations?
Infeasible from an efficiency perspective to look through all inventory as it scales.
Stylists can’t keep all products in their memories while trying to locate the best items for each client.
MOTIVATION
Inventory Scaling:
Human Ability:
Why Recommendations?
Infeasible from an efficiency perspective to look through all inventory as it scales.
Stylists can’t keep all products in their memories while trying to locate the best items for each client.
Business Success:
Aid stylists in making the best decisions to better please our clients.
MOTIVATIONOur goal at Stitch Fix
Total Inventory
Recommendation Algo
Stylists
Filtered Items
1 2 3 4 5
Final Items Sent
COMPUTER VISION
New Clients
New Clothing
Cold Start Problem
No or sparse purchasing information, so how can we supplement this?
COMPUTER VISION
New Clients
New Clothing
Cold Start Problem
No or sparse purchasing information, so how can we supplement this?
Perception
Fashion can be difficult to describe via text/categorization.
Many times it’s easier to show what you like.
TURN TO IMAGES
• Style/fashion is primarily visual.
• We wish to use images for modeling purposes.
• Heuristics for how we process image data
unknown or quite complex.
• We don’t want to have to develop image
features.
• Turn to deep learning to learn the feature
extraction.
OUTLINE
1. Brief Introduction to NNs
2. Deep Learning for Fashion Imagery
3. Recommendations and Social Media
4. Results
5. Conclusions
NEURAL NETWORKS
http://www.wired.com/2013/02/three-awesome-tools-scientists-may-use-to-map-your-brain-in-the-future/
http://googleresearch.blogspot.com/2015/06/inceptionism-going-deeper-into-neural.html
WhoaDude!
http://googleresearch.blogspot.com/2015/06/inceptionism-going-deeper-into-neural.html
Begin with input: 1 2 3 4 layer 1 (Input)
5 6
layer 2
f
(l)i (x) = tanh
0
@X
j
W
(l)ij x
(l�1)j + b
(l)
1
A
INTRO TO NEURAL NETS
Begin with input: 1 2 3 4 layer 1 (Input)
5 6
layer 2
f
(l)i (x) = tanh
0
@X
j
W
(l)ij x
(l�1)j + b
(l)
1
A
layer 3 (output)
Transform data repeatedly with non-linear function.
f
(1) � · · · � f (n)(x)
INTRO TO NEURAL NETS
1 2 3 4 layer 1(Input)
5 6
layer 2
layer 3(output)
Calculate loss function and update weights
f
(1) � · · · � f (n)(x)
L(xout
, y) =
MSEz }| {1
m
mX
k=1
(xk � yk)2
Begin with input:
f
(l)i (x) = tanh
0
@X
j
W
(l)ij x
(l�1)j + b
(l)
1
A
Transform data repeatedly with non-linear function.
INTRO TO NEURAL NETS
1 2 3 4 layer 1(Input)
5 6
layer 2
layer 3(output)
L(xout
, y) =
MSEz }| {1
m
mX
k=1
(xk � yk)2
W (l)⇤ij = W (l)
ij
✓1� ↵
@L@Wij
◆
Calculate loss function and update weights
f
(1) � · · · � f (n)(x)
Begin with input:
f
(l)i (x) = tanh
0
@X
j
W
(l)ij x
(l�1)j + b
(l)
1
A
Transform data repeatedly with non-linear function.
INTRO TO NEURAL NETS
1 2 3 4 layer 1(Input)
5 6
layer 2
layer 3(output)
L(xout
, y) =
MSEz }| {1
m
mX
k=1
(xk � yk)2
W (l)⇤ij = W (l)
ij
✓1� ↵
@L@Wij
◆@L
@W
(l)ij
=
✓@L
@x
out
◆✓@x
out
@f
(n�1)
◆· · ·
@f
(l)
@W
(l)ij
!
Calculate loss function and update weights
f
(1) � · · · � f (n)(x)
Begin with input:
f
(l)i (x) = tanh
0
@X
j
W
(l)ij x
(l�1)j + b
(l)
1
A
Transform data repeatedly with non-linear function.
INTRO TO NEURAL NETS
RECS AND SOCIAL MEDIA
Clients give Pinterest board to visually indicate fashion tastes.
Match pinned images to our own styles.
RECS AND SOCIAL MEDIA
Clients give Pinterest board to visually indicate fashion tastes.
Match pinned images to our own styles.
Strategies
RECS AND SOCIAL MEDIA
Clients give Pinterest board to visually indicate fashion tastes.
Match pinned images to our own styles.
Strategies
Attribute extraction and matching.
RECS AND SOCIAL MEDIA
Clients give Pinterest board to visually indicate fashion tastes.
Match pinned images to our own styles.
Strategies
Attribute extraction and matching. Visual feature similarity.
RECS AND SOCIAL MEDIA
Clients give Pinterest board to visually indicate fashion tastes.
Match pinned images to our own styles.
Strategies
Attribute extraction and matching. Visual feature similarity.
Metric learning.
RECS AND SOCIAL MEDIA
Clients give Pinterest board to visually indicate fashion tastes.
Match pinned images to our own styles.
Strategies
Attribute extraction and matching. Visual feature similarity.
Metric learning. …or some combination.
VISUAL FEATURES
Use pre-trained extracted features.
Compare image features with metric of your choice
Cosine Euclidean etc,
CHALLENGESQuery Image
Top 5 Results
Sometimes things don’t work out so well…
Need system to compare images across separate domains
METRIC LEARNING
New Metricas Objective
Anch
orPo
sitive
Neg
ative
Triplet or Contrastive Loss
https://arxiv.org/abs/1404.4661
Ltriplet(a, p, n) =1
N
NX
i=1
max {d(f(ai), f(pi))� d(f(ai), f(ni)) +m, 0}!
METRIC LEARNING
https://arxiv.org/abs/1511.05939
m m
Positive
Negative
Before Training After Training Before Training After Training
METRIC LEARNING
https://arxiv.org/abs/1511.05939
m m
Positive
Negative
Before Training After Training Before Training After Training
Learn an embedding that obeys the similarity constraints.
similarity score = d�query, inventory
�
CONCLUSIONS
1. Social media images can help make better recommendations.
a) Alleviate cold start.
b) Provide new features/data for recommendations.
2. Cross-domain image matching can be difficult, but is made easier with deep learning.
3. There’s enormous potential moving forward with this type of work.
a) Attribute labeling and trend tracking.
b) Predictive models for purchasing probability.
THANK YOU!
@teejosaur
/in/tjtorres
@tjtorres