影像切割、超像素自動調變與局部匹配用於立體匹配與光場影像之深度估測

自從第一台光場相機在2012年11月推出後，光場相機的研究與應用逐漸被重視，與傳統相機不同的是，光場相機不只能記錄光的強度，還能得知光的角度資訊。除此之外，僅僅透過一次拍攝便可以得到足夠的資訊去對影像做重組、深度估測以及不同的對焦。另一方面，立體匹配也是一個熱門的研究主題，我們可以藉由兩張相同場景、不同角度的影像得出物體的深度，而深度資訊可以進一步地去做許多應用。除此之外，立體匹配當中的局部匹配被廣泛地應用在光場相機的重組和深度估測處理上。在這篇論文中，我們主要分為三部分。第一部分是藉由局部匹配改良既有的光場影像重組技術。第二部分是提出新的立體匹配，是以影像切割為主，配合超像素的自動調變以及能適用任意切割形狀比對的局部匹配演算法和一些進一步的處理。第三部分是針對光場影像的深度估測，尤其是部分難以藉由立體匹配得到良好深度資訊的影像，我們藉由影像切割以及局部最佳對焦焦距的方式去得到深度資訊。

關鍵字

立體匹配；影像切割；超像素；局部匹配；聚焦光場相機；光場；影像重組

並列摘要

After the releasing of Plenoptic camera in November 2012, the research of light field camera is getting popular in recent years. The main difference between Plenoptic camera and traditional camera is that the angular information of light ray can be acquired by the former one. With one shot only, we can reconstruct the depth of scene and render the micro images into one final image from different views. We can also change the focal distance to make near or far objects clear. These are the appealing advantages of Plenoptic camera. Stereo matching is also a popular research topic since we can obtain depth information by two images from left and right views. Many applications can be done if we have the accurate depth information about an image. Besides, the concept of stereo matching can be used in light field image rendering to get better result. In this thesis, we divide the contents into three parts. The first part is to enhance the original rendering technique used in light field image with better local matching algorithm added. The second part is stereo matching. We use segmentation to help stereo matching and find an auto adjustment method to decide the best number of superpixel for each image. We also find a new local matching algorithm that is efficient especially for stereo matching after segmentation. Some techniques that can further increase the result are also added. The third part is a new depth estimation method used in light field image especially for some light field images that are hard to estimate depth by stereo matching. The method to recover depth information is based on segmentation and images from different focal distance.

並列關鍵字

stereo matching ； segmentation ； superpixel ； local matching algorithm ； focused plenoptic camera ； light field ； image rendering

參考文獻

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影像切割、超像素自動調變與局部匹配用於立體匹配與光場影像之深度估測

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