fields (dealing with big data) Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) [1] C. Chen et al. 2014 CVPR [2] C. Shang et al. 2017, IEEE Int Conf Big Data. Pose View Example of Missing data problems in Computer vision[1] and Medical data[2] Age Gender Heart rate Subjects Obesity …
GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) • Consequences of Missing data • Introduce bias/error because of incomplete data • What is ‘imputation’? • Replace missing data with substituted values è Algorithms for the numerical data Extend the problem to Missing ‘Image’ Imputation on multi-domain. Matrix Completion (Mazumder et al., 2010) Denoising Auto-Encoder (Vincent et al., 2008, Gondora et al. 2017) GAIN, Generative Adversarial Imputation Nets (Yoon et al., 2018)
imaging • Multiple contrast images for cancer diagnosis[1] • Missing Contrast problem • Needs #2 – illumination images • Facial images from various angles of illumination • Finding the specific illumination (standard) Figure. Example for missing images in medical imaging Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) [1] A. Drevelegas et al. 2011, Imaging modalities in brain tumors Figure. Example for missing images in illumination database T1w T2w T1-FLAIR T2-FLAIR -90º -45º 0º 45º 90º
technique called Collaborative Generative Adversarial Network (CollaGAN) Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) Figure. Example for missing illumination imputation Figure. Example for missing MR contrast imputation
D Loss Real Sampler, z Fake min $ max ' ( ), + = -.~01232(.) log ) 9 + -;~0<(;) [log(1 − ) + @ )] [1] I. Goodfellow et al. 2014, NIPS Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis)
al. 2017, ICCV [2] Kim, T et al. 2017, ICML G_cat G_dog Real D_cat Loss D_dog Loss Real Real Real Fake Fake min $ max ' ( )* , ), , -* , -, = /0~23454(0) log )* ;* + /=~23454(=) [log(1 − )* -* A )] +/=~23454(=) log ), A, + /0~23454(0) [log(1 − ), -, ; )] Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis)
on scalability • Not shared feature learning • StarGAN[3] & RadialGAN[4] • Deals with multiple domain • Shared learning on latent space • Single input to single output • Cannot handle the multiple inputs [1] Zhu, JY et al. 2017, ICCV [2] Kim, T et al. 2017, ICML, [3] Choi, Y et al. 2017, CVPR [4] Yoon, J et al. 2018, ICML #Domain #G #D 2 2 2 3 6 3 ! "# 4 ⋮ ⋮ ⋮ N N(N-1) N Figure. Example of 4-distinct Cross-domain model[3] and numbers of G and D for N cross-domain models. Figure. Concepts of StarGAN[3] and RadialGAN[4] Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis)
GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) • CycleGAN & StarGAN • Try to approach the problem by image-to-image translation way. • Limitations: Scalability, Single input to single output CycleGAN[1] StarGAN[2] [1] Zhu, JY et al. 2017, ICCV [2] Choi, Y et al. 2017, CVPR
GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) • CycleGAN & StarGAN • Try to approach the problem by image-to-image translation way. • Limitations: Scalability, Single input to single output [1] Zhu, JY et al. 2017, ICCV [2] Choi, Y et al. 2017, CVPR CollaGAN
Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) works on Various number of inputs (with a help of input dropout) # Inputs = 2 # Inputs = 1 CollaGAN
Using Multiple inputs • Using Single Generator • Using Adversarial Model • Using Single Discriminator • Using Multiple Cycle Consistency Multiple Inputs Single Generator Single Discriminator Adversarial model Multiple Cycle Consistency
90 º Target Proposed StarGAN[2] CycleGAN[1] 0 º CollaGAN reconstructs not only the overall illumination but also the details of illumination from the nose, chin and cheeks. [1] Zhu, JY et al. 2017, ICCV [3] Choi, Y et al. 2017, CVPR Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis)
• Some of inputs may not contribute Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis)
• Some of inputs may not contribute Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) • To achieve the “collaborative” learning • Apply random nulling on N inputs (Missing N) : input dropout
GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis) Missing 5 Missing 1 Missing 2 Missing 3 Missing 4 Missing 6 Target Missing 7 w/o dropout dropout Sad Amount of input information • Robust performance on various missing # • More input information à Better reconstruction quality
multiple input images • Multiple cycle consistency • Multi-domain : Single G & Single D • Synergistically combining the information from the available data with a help of input dropout. • Produces images with higher visual quality compared to the existing methods. Poster #135 - CollaGAN: Collaborative GAN for Missing Image Data Imputation (Tues, June 18, 15:20-18:00, Poster1.2, Synthesis)
Junyoung Kim, Won-Jin Moon, Jong Chul Ye KONKUK UNIVERSITY MEDICAL CENTER Thank you for your attention. Poster #135 (Tues, June 18, 15:20-18:00, Poster1.2) Come over to my poster for more discussions!