We describe a highly functional prototype system for searching by visual features in an image database. The VisualSEEk system is novel in that the user forms the queries by diagramming spatial arrangements of color regions. The system finds the images that contain the most similar arrangements

Abstract. We present a novel method for generic visual categorization: the problem of identifying the object content of natural images while generalizing across variations inherent to the object class. This bag of keypoints method is based on vector quantization of affine invariant descriptors

We introduce a new interactive system: a game that is fun and can be used to create valuable output. When people play the game they help determine the contents of images by providing meaningful labels for them. If the game is played as much as popular online games, we estimate that most images

Abstract—Visual surveillance in dynamic scenes, especially for humans and vehicles, is currently one of the most active research topics in computer vision. It has a wide spectrum of promising applications, including access control in special areas, human identification at a distance, crowd flux

The explosive growth of applications involving digital audio-visual material is driving the need for more rich content description. In this paper, we present a design process for audio-visual content description. The process involves constructing a conceptual model in which entities, attributes

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In instructional videos of chalk board presentations, the visual content refers to the text and figures written on the boards. Existing methods on video summarization are not effective for this video domain because they are mainly based on low-level image features such as color and edges

with the parent node. Experiments with datasets of hundreds and thousands of images show that shallow trees can produce clustering into "meaningful" classes. Visual-content search trees can be used to automate image retrieval by content, or help a human to interactively search for images. 1

To achieve flexible visual content adaptation for multimedia communications, the ISO/IEC MPEG and ITU-T VCEG form the Joint Video Team (JVT) to develop a scalable video coding

In this paper, we propose a semi-fragile watermarking technique that accepts JPEG lossy compression on the watermarked image to a pre-determined quality factor, and rejects malicious attacks. The authenticator can identify the positions of corrupted blocks, and recover them with approximation of the original ones. In addition to JPEG compression, adjustments of the brightness of the image within reasonable ranges, are also acceptable using the proposed authenticator. The security of the proposed method is achieved by using the secret block mapping function which controls the signature generating/embedding processes. Our authenticator is based on two invariant properties of DCT coecients before and after JPEG compressions. They are deterministic so that no probabilistic decision is needed in the system. The first property shows that if we modify a DCT coecient to an integral multiple of a quantization step, which is larger than the steps used in later JPEG compressions, then this coecient can be exactly reconstructed after later acceptable JPEG compression. The second one is the invariant relationships between two coecients in a block pair before and after JPEG compression. Therefore, we can use the second property to generate authentication signature, and use the first property to embed it as watermarks. There is no perceptible degradation between the watermarked image and the origianl. In additional to authentication signatures, we can also embed the recovery bits for recovering approximate pixel values in corrupted areas. Our authenticator utilizes the compressed bitstream, and thus avoids rounding errors in reconstructing DCT coecients. Experimental results showed the effectiveness of this system. The system also guarantees no false alarms, i.e., no acceptable JPEG comp...