Title
Content-adaptive image downscaling
Abstract
This paper introduces a novel content-adaptive image downscaling method. The key idea is to optimize the shape and locations of the downsampling kernels to better align with local image features. Our content-adaptive kernels are formed as a bilateral combination of two Gaussian kernels defined over space and color, respectively. This yields a continuum ranging from smoothing to edge/detail preserving kernels driven by image content. We optimize these kernels to represent the input image well, by finding an output image from which the input can be well reconstructed. This is technically realized as an iterative maximum-likelihood optimization using a constrained variation of the Expectation-Maximization algorithm. In comparison to previous downscaling algorithms, our results remain crisper without suffering from ringing artifacts. Besides natural images, our algorithm is also effective for creating pixel art images from vector graphics inputs, due to its ability to keep linear features sharp and connected.
Year
DOI
Venue
2013
10.1145/2508363.2508370
ACM Trans. Graph.
Keywords
Field
DocType
content-adaptive kernel,pixel art image,output image,image content,content-adaptive image downscaling,previous downscaling algorithm,input image,novel content-adaptive image,natural image,local image feature,expectation-maximization algorithm,downscaling
Ringing artifacts,Computer vision,Vector graphics,Mathematical optimization,Feature (computer vision),Computer science,Smoothing,Gaussian,Ranging,Artificial intelligence,Pixel,Upsampling
Journal
Volume
Issue
ISSN
32
6
0730-0301
Citations 
PageRank 
References 
7
0.51
14
Authors
3
Name
Order
Citations
PageRank
johannes kopf1145865.35
Ariel Shamir23929174.85
Pieter Peers3110955.34