image inpainting via generative multi-column convolutional neural networks · 2019-11-29 · image...

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Image Inpainting via Generative Multi-column Convolutional Neural Networks Yi Wang 1 Xin Tao 1,2 Xiaojuan Qi 1 Xiaoyong Shen 2 Jiaya Jia 1,2 1 The Chinese University of Hong Kong 2 YouTu Lab, Tencent Introduction Our Model Experiments Target Estimating suitable pixel information to fill holes in images. Motivations A typical inpainting method focuses on Features for generation: to consider features as a group of different components and combine both global semantics and local textures. Reliable similar patches: using neighboring patches to regularize the generated ones. Spatial-variant constraints: pixels close to area boundary are with few choices, while the central part can be less constrained. ID - MRF regularization To take MRF-like regularization only in the training phase. For neural patches and extracted from and respectively, their relative similarity is: RS , = exp( (,) ℎ×( max , +) ), and it is further normalized as: RS , = RS , σ RS , . The final ID-MRF loss: =ℒ 4_2 + σ =3 4 _2, where = −log( 1 σ max RS(, )). Spatial variant reconstruction loss To propagate the confidence of known pixels to unknown ones, = ⊙ , where =−+ −1 and 0 =. Our confidence-driven loss is: = ||( − ( , ; )) ⊙ || 1 Adversarial loss = − ~ℙ ; + ~ℙ [(|| △ ( ) ⊙ || 2 − 1) 2 ] User studies Quantitative Evaluation Our Model Overall framework GMCNN: generative multi-column convolutional neural network; CE: context encoder; MSNPS: multi-scale neural patch synthesis; CA: contextual attention. Input CE MSNPS CA Ours Input CA Ours Input CA Ours Input CA Ours

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Page 1: Image Inpainting via Generative Multi-column Convolutional Neural Networks · 2019-11-29 · Image Inpainting via Generative Multi-column Convolutional Neural Networks Yi Wang1 Xin

Image Inpainting via Generative Multi-column Convolutional Neural Networks

Yi Wang1 Xin Tao1,2 Xiaojuan Qi1 Xiaoyong Shen2 Jiaya Jia1,2

1The Chinese University of Hong Kong 2YouTu Lab, Tencent

Introduction Our Model Experiments

Target• Estimating suitable pixel information to fill

holes in images.

MotivationsA typical inpainting method focuses on

• Features for generation: to consider features as a

group of different components and combine both

global semantics and local textures.

• Reliable similar patches: using neighboring

patches to regularize the generated ones.

• Spatial-variant constraints: pixels close to area

boundary are with few choices, while the central

part can be less constrained.

ID-MRF regularization

To take MRF-like regularization only in the

training phase. For neural patches 𝐯 and 𝐬 extracted

from 𝐘𝑔𝐿 and 𝐘𝐿 respectively, their relative

similarity is: RS 𝐯, 𝐬 = exp(𝜇(𝐯,𝐬)

ℎ×( max𝐫∈𝜌𝐯 𝐘𝐿

𝜇 𝐯,𝐫 +𝜖)), and

it is further normalized as:

RS 𝐯, 𝐬 =RS 𝐯, 𝐬

σ𝐫∈𝜌𝐯 𝐘𝐿 RS 𝐯, 𝐫

.

The final ID-MRF loss:

ℒ𝑚𝑟𝑓 = ℒ𝑀 𝑐𝑜𝑛𝑣4_2 + σ𝐭=34 𝑐𝑜𝑛𝑣𝐭_2,

where ℒ𝑀 𝐿 = −log(1

𝑍σ𝐬∈𝐘𝐿max

𝐯∈𝐘𝑔𝐿RS(𝐯, 𝐬)).

Spatial variant reconstruction lossTo propagate the confidence of known pixels to

unknown ones,

𝐌𝑤𝑖 = 𝑔 ∗ ഥ𝐌𝑖 ⊙𝐌,

where ഥ𝐌𝑖 = 𝟏 −𝐌+𝐌𝑤𝑖−1 and 𝐌𝑤

0 = 𝟎.

Our confidence-driven loss is:

ℒ𝑐 = ||(𝐘 − 𝐺( 𝐗,𝐌 ; 𝜃)) ⊙𝐌𝑤||1

Adversarial lossℒ𝑎𝑑𝑣 = −𝐸𝐗~ℙ𝐗 𝐷 𝐺 𝐗; 𝜃

+𝜆𝑔𝑝𝐸𝐗~ℙ𝐗[(|| △𝐗 𝐷(𝐗)⊙𝐌𝑤||2 − 1)2]

User studies

Quantitative Evaluation

Our Model

Overall framework

GMCNN: generative multi-column convolutional neural network; CE: context

encoder; MSNPS: multi-scale neural patch synthesis; CA: contextual attention.

Input CE MSNPS CA Ours

Input CA Ours Input CA Ours

Input CA Ours