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17
Seam carving with improved edge preservation
- In Proceedings of IS&T/SPIE Electronic Imaging (EI) on Multimedia on Mobile Devices
, 2010
"... Figure 1. Our new algorithm compared to scaling and regular seam carving with forward energy. In this example, the width is reduced to 60 % of the original size. In this paper, we propose a new method to adapt the resolution of images to the limited display resolution of mobile devices. We use the s ..."
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Cited by 7 (5 self)
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Figure 1. Our new algorithm compared to scaling and regular seam carving with forward energy. In this example, the width is reduced to 60 % of the original size. In this paper, we propose a new method to adapt the resolution of images to the limited display resolution of mobile devices. We use the seam carving technique to identify and remove less relevant content in images. Seam carving achieves a high adaptation quality for landscape images and distortions caused by the removal of seams are very low compared to other techniques like scaling or cropping. However, if an image depicts objects with straight lines or regular patterns like buildings, the visual quality of the adapted images is much lower. Errors caused by seam carving are especially obvious if straight lines become curved or disconnected. In order to preserve straight lines, our algorithm applies line detection in addition to the normal energy function of seam carving. The energy in the local neighborhood of the intersection point of a seam and a straight line is increased to prevent other seams from removing adjacent pixels. We evaluate our improved seam carving algorithm and compare the results with regular seam carving. In case of landscape images with no straight lines, traditional seam carving and our enhanced approach lead to very similar results. However, in the case of objects with straight lines, the quality of our results is significantly better.
Maintaining temporal coherence in video retargeting using mosaic-guided scaling
- IEEE Trans. Image Process
, 2011
"... Abstract—Video retargeting from a full-resolution video to a lower resolution display will inevitably cause information loss. Content-aware video retargeting techniques have been studied to avoid critical visual information loss while resizing a video. Maintaining the spatio-temporal coherence of a ..."
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Abstract—Video retargeting from a full-resolution video to a lower resolution display will inevitably cause information loss. Content-aware video retargeting techniques have been studied to avoid critical visual information loss while resizing a video. Maintaining the spatio-temporal coherence of a retargeted video is very critical on visual quality. Camera motions and object motions, however, usually make it difficult to maintain temporal coherence using existing schemes. In this paper, we propose the use of a panoramic mosaic to guide the scaling of corresponding regions of video frames in a video shot to ensure good temporal coherence. In the proposed method, after aligning video frames in a shot to a panoramic mosaic constructed for the shot, a global scaling map for these frames is derived from the panoramic mo-saic. Subsequently, the local scaling maps of individual frames are derived from the global map and is further refined according to spatial coherence constraints. Our experimental results show that the proposed method can effectively maintain temporal coherence so as to achieve good visual quality even a video contains camera motions and object motions. Index Terms—Spatio-temporal coherence, video adaptation, video retargeting, video scaling. I.
Aesthetics-based stereoscopic photo cropping for heterogeneous displays
- IEEE Trans. Multimedia
, 2012
"... Abstract—Stereoscopic displays are becoming ubiquitous, ranging from large 3-D TVs to small mobile phones. Stereoscopic photos need to be carefully adapted to be effectively viewed on the displays other than originally intended. In this paper, we present a method that can automatically crop and scal ..."
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Abstract—Stereoscopic displays are becoming ubiquitous, ranging from large 3-D TVs to small mobile phones. Stereoscopic photos need to be carefully adapted to be effectively viewed on the displays other than originally intended. In this paper, we present a method that can automatically crop and scale an existing stereoscopic photo to a variety of displays while preserving its aesthetic value. We formulate stereoscopic photo adaptation as an optimization problem that aims to preserve the aesthetic value of the input photo. We define a wide range of energy terms to preserve the stereoscopic photo aesthetics by borrowing rules from stereoscopic photography. Our experiments on a wide variety of stereoscopic photos demonstrate that our method can robustly produce display-dependent stereoscopic photos that deliver pleasant viewing experiences. Index Terms—Aesthetics, multimedia authoring, photo crop-ping, stereoscopic photography. I.
Semi-automatic Registration of Videos for Improved Watermark Detection
"... Virtually every video watermarking technology can benefit from comparison with the original content. For non-blind schemes it is fundamental; for others it is an improvement to increase the watermark’s signal-to-noise ratio by subtract-ing the content that is often noise to the detector. A direct fr ..."
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Virtually every video watermarking technology can benefit from comparison with the original content. For non-blind schemes it is fundamental; for others it is an improvement to increase the watermark’s signal-to-noise ratio by subtract-ing the content that is often noise to the detector. A direct frame-by-frame comparison of the videos is not possible due to the fact that illegal copies of videos usually differ signifi-cantly from their originals caused by different spatial resolu-tion or frame rates, geometric distortions from capturing, or targeted attacks. In this paper, we present a software tool that enables the semi-automatic temporal and spatial syn-chronization of frames and pixels of two similar videos. This process is called registration. We put our focus on utilizing human capabilities with the smallest possible effort, to allow a high overall performance and precision of the registration. An efficient graphical user interface supports the users and visualizes the results of all steps. In addition, we specifically distinguish digitally reproduced copies from analog (cam-corded) copies in which two or more frames are blended into a new frame.
Stereoscopic Seam Carving with Temporal Consistency
"... In this paper, we present a novel technique for seam carving of ste-reoscopic video. It removes seams of pixels in areas that are most likely not noticed by the viewer. When applying seam carving to stereoscopic video rather than monoscopic still images, new chal-lenges arise. The detected seams mus ..."
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In this paper, we present a novel technique for seam carving of ste-reoscopic video. It removes seams of pixels in areas that are most likely not noticed by the viewer. When applying seam carving to stereoscopic video rather than monoscopic still images, new chal-lenges arise. The detected seams must be consistent between the left and the right view, so that no depth information is destroyed. When removing seams in two consecutive frames, temporal con-sistency between the removed seams must be established to avoid flicker in the resulting video. By making certain assumptions, the available depth information can be harnessed to improve the quali-ty achieved by seam carving. Assuming that closer pixels are more important, the algorithm can focus on removing distant pixels first. Furthermore, we assume that coherent pixels belonging to the same object have similar depth. By avoiding to cut through edges in the depth map, we can thus avoid cutting through object boundaries.
Analysis and Retargeting of Ball Sports Video
"... The quality achieved by simply scaling a sports video to the limited display resolution of a mobile device is of-ten insufficient. As a consequence, small details like the ball or lines on the playing field become unrecognizable. In this paper, we present a novel approach to analyzing court-based ba ..."
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The quality achieved by simply scaling a sports video to the limited display resolution of a mobile device is of-ten insufficient. As a consequence, small details like the ball or lines on the playing field become unrecognizable. In this paper, we present a novel approach to analyzing court-based ball sports videos. We have developed new tech-niques to distinguish actual playing frames, to detect play-ers, and to track the ball. This information is used for ad-vanced video retargeting, which emphasizes essential con-tent in the adapted videos. We evaluate the precision and re-call achieved in the analysis and measure the computational time taken. In addition, we compare our new approach to other video retargeting techniques based on scaling, crop-ping, and seam carving. 1.
Approved by:
, 2012
"... Real-time content-aware video retargeting on the Android platform for tunnel vision assistance Thomas Knack Follow this and additional works at: ..."
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Real-time content-aware video retargeting on the Android platform for tunnel vision assistance Thomas Knack Follow this and additional works at:
Low-Overhead Content-Adaptive Spatial Scalability for Scalable Video Coding
"... Abstract—To support spatial scalability, the scalable extension of H.264/AVC (SVC) uses video cropping or uniform scaling to downscale the original higher-resolution (HR) sequence to a lower resolution (LR) sequence. Both operations, however, will cause critical visual information loss in the resize ..."
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Abstract—To support spatial scalability, the scalable extension of H.264/AVC (SVC) uses video cropping or uniform scaling to downscale the original higher-resolution (HR) sequence to a lower resolution (LR) sequence. Both operations, however, will cause critical visual information loss in the resized frames. To address the problem, we propose a low-overhead content-adaptive spatial scalability SVC (CASS-SVC) coder consisting of three main modules: a mosaic-guided video retargeter, a side-information coder, and a non-homogeneous inter-layer predictive coder. The proposed video retargeting scheme first constructs a panoramic mosaic for each video shot to obtain a compact shot-level global scaling map which is then used to derive the scaling maps of individual frames in the shot. The side information required for the non-homogeneous scaling, including the global scaling maps and the spatial corresponding positions of individual frames to the panoramic mosaic, are then efficiently coded by the side-infor-mation coder. The non-homogeneous interlayer prediction coding tools are used to provide good predictions to reduce the bitrates for coding the HR frames. Our simulation results demonstrate that, compared to existing CASS-SVC coders, our method cannot only well preserve subjective quality of important content in the LR sequence, but also significantly improves the coding efficiency of HR sequence. Index Terms—Inter-layer prediction, scalable video coding, spa-tial scalability, video adaptation, video retargeting. I.
Pratap Pal
"... This paper describes that how we can implement various techniques using “Seam Carving for Image and Video Retargeting ” which would solve many problems that arise during the displaying, scaling, resizing of the various images and videos [1,2,3]. In this paper you will go through many techniques and ..."
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This paper describes that how we can implement various techniques using “Seam Carving for Image and Video Retargeting ” which would solve many problems that arise during the displaying, scaling, resizing of the various images and videos [1,2,3]. In this paper you will go through many techniques and their implementations that have been proposed by many authors using Seam Carving for Image and Video Retargeting. Seam carving that is also known as image retargeting, scaling, liquid resizing, or liquid rescaling; is generally an algorithm for image resizing that was developed and introduced by Shai Avidan, of the Mitsubishi Electric Research Laboratories (MERL), and Ariel Shamir, of the Interdisciplinary Center and MERL[1]. As per the algorithm suggested by the author, you have to establish number of seams in the selected image and further automatically remove seams to reduce the size of the image. The same approach is adopted for video retargeting except the fact that you use video frames instead of objects in the image. The paper discusses various approaches that have been adopted by various authors in this respect.
Video Retargeting: Video Saliency and Optical Flow Based Hybrid Approach
"... As smart phones, tablets and similar computing devices become an integral part of our lives, we increasingly watch various types of streaming visual data on the dis-play of those devices, especially as cloud video services become ubiquitous. One challenge is to present videos on diverse devices with ..."
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As smart phones, tablets and similar computing devices become an integral part of our lives, we increasingly watch various types of streaming visual data on the dis-play of those devices, especially as cloud video services become ubiquitous. One challenge is to present videos on diverse devices with an acceptable quality. Video retargeting is the key technology in video adaptation of cloud based video streaming. The most important challenge of video retargeting is to retain the shape of important objects, while ensuring temporal smoothness and coherence. We propose in this paper a new ap-proach that adopts to the content of the video. We de-scribe a cropping video retargeting method that ensures temporal coherence while enforcing spatial constraints by a saliency method. The average motion dynamics is calculated for each frame with optical flow and merged with the information of the user attention model for a given video. The resulting information is used to esti-mate a cropping window size. The output is a video that preserves important actions and the important parts of the scene. The results are promising in respect to over-coming the temporal and spatial challenges of video re-targeting. 1
