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Semi-Automatic Image Annotation. Liu Wenyin, Susan Dumais, Yanfeng Sun, HongJiang Zhang, Mary Czerwinski and Brent Field Microsoft Research. Outline. Introduction: What, Why, and How Our Approach: Semi-Automatic Processes and Algorithms Automated Performance Evaluation
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Semi-Automatic Image Annotation Liu Wenyin, Susan Dumais, Yanfeng Sun, HongJiang Zhang, Mary Czerwinski and Brent Field Microsoft Research
Outline • Introduction: What, Why, and How • Our Approach: • Semi-Automatic • Processes and Algorithms • Automated Performance Evaluation • Usability Studies • Concluding Remarks
What it is and Why • Image Annotation is a process of labeling images with keywords to describe semantic content • For image indexing and retrieval in image databases • Annotated images can be found more easily using keyword-based search
Image Annotation Approaches • Totally Manual Labeling (Gong et al., 1994) • Enter keywords when image is loaded/registered/browsed • Accurate but labor-intensive, tedious, and subjective • Direct Manipulation Annotation (Shneiderman and Kang 2000) • Drag and drop keywords (from a predefined list ) onto image • Still manual, also limited to predefined keywords (can’t be many) • Automatic Approaches: Efficient but less reliable and not always applicable compared to human annotation---how to grab this when no text context? • By Image Understanding/Recognition (Ono et al. 1996) • By Associating with environmental text (Shen et al. 2000; Srihari et al. 2000; Lieberman 2000)
Our Proposed Approach • Semi-Automatic Approach • User provides initial query and relevance feed back. • Feedback used to “semi-automatically” annotate images • Trade-off between manual and automatic • Achieve both accuracy and efficiency • Increase productivity • Employ Content-Based Image Retrieval (CBIR), text matching, and Relevance Feedback (RF)
Algorithms for Matching • Visual Similarity Measurement • Features: color histogram/moments/coherence, Tamura coarseness, pyramid wavelet texture, etc • Distance model: Euclidean distance • Semantic (Keywords) Similarity Measurement • Features: keyword vectors, TF*IDF • Metrics: dot product and cosine normalization • Overall similarity: weighted average of the above two
Algorithms to Refine Search • Image Relevance Feedback Algorithms • There are many algorithms can be used • Cox et al. (1996) • Rui and Huang (2000) • Vasconcelos and Lippman (1999) • Lu et al. 2000 is employed in MiAlbum for text and images • Modified Rocchio’s Formula • Uses both semantics (keywords) and image-based features during relevance feedback
Semi-Automatic Annotation During Relevance Feedback • In each keyword-query search cycle • When positive and negative examples provided, • Increase the weight of the keyword for all positive examples • Decrease the weight of the keyword for all negative examples • Relevance feedback algorithm refines and puts more relevant images in top ranks for further selection as positive examples • Repeat the feedback process
Possible Future Automatic Annotation • When a new image is added… • Find top N similar images using image metrics • Most frequent keywords among annotations of these top N similar images are potential annotations, and could be automatically added with low weight or presented to user as potential annotations • TBD--Need to be confirmed in further RF process
Automated Performance Evaluation • Test Ground Truth Database • 12,200 images in 122 categories from Corel DB • Category name is ground truth annotation • Automatic Experimental Process • Use category name as query feature for image retrieval • Among first 100 retrieved images, those belonging to this category are used as positive feedback examples others as negative • Performance Metrics • Retrieval accuracy and annotation coverage
Usability Studies • Objectives • 2 studies examined overall usability of MiAlbum • The usability of the semi-automatic annotation strategy • Tasks • Import pictures, annotate pictures, find pictures, and use relevance feedback • Questionnaires including but not limited to • Overall ease of entering annotations for images • Impact of annotation on ease of searching for images • Satisfaction of search refinement & relevance feedback
Questionnaire Results • Overall ease of entering annotations: 5.6/7.0 • Ease to search annotated photos: 6.3/7.0 • Intuitiveness of refining search: 4.1/7.0 • Other Comments • Positive on “semi-automatic”: (1) When using the up and down hands the software automatically annotated the photos chosen. (2) The ability to rate pictures on like/dislike and have the software go from there. • Negative: difficulties in understanding the feedback process and how the matching algorithm operated.
Concluding Remarks • A Semi-automatic Annotation Strategy Employing • Available image retrieval algorithms and • Relevance feedback • Automatic Performance Evaluation • Efficient compared to manual annotation? • More accurate than automatic annotation • Usability Studies • Preliminary usability results are promising • Need to improve the discoverability of the feedback process and the underlying matching algorithm