Image based solar position editing and relighting

Türe, Murat
Capturing perfect photos is a challenging task that requires good composition andtiming. Failure to achieve them may result in ‘missing the moment’. For example,when shooting photos at sunset the sun quickly disappears behind the horizon. Inthis thesis, a new image editing algorithm is defined to let the user change the sunposition in a photo. This is the first study in the literature which tries to solve this par-ticular image editing problem. The algorithm can be divided into three parts. First,the image pixels are segmented into different categories, namely the sky, clouds, sun,horizon, and the foreground. Then, a real-time rendered sky is replaced with the oldsky to allow changing the position of the sun. A color transfer algorithm is used to cope with the differences that cannot be accurately deduced from a single photo suchas exposure, atmospheric parameters, and the camera response curve. Furthermore,techniques for relighting the cloud and foreground pixels are proposed. Finally, theserelighted pixels are blended together by using the labels from the segmentation partof the algorithm to generate the final image. The proposed image editing technique works in real-time to provide instant feedback to the user. It also provides intutiveuser controls to allow overriding and fine-tuning various automatically detected parameters.


An Evaluation of ghost removal algorithms for exposure fusion
Kutlu, Tuğser; Akar, Gözde; Department of Electrical and Electronics Engineering (2015)
In high dynamic range imaging (HDR), the goal is to capture a scene with a higher dynamic range than the camera capable of capturing with a single exposure. Similar to HDR, exposure fusion is a process that takes multiple images and combines them to create a single dynamically enhanced image by only keeping the properly exposed elements. When using multiple images, local motion of objects can influence the quality of the final image in such a way that local motion of objects causes a ghost artifact. In this...
Ghost Removal in High Dynamic Range Images
Khan, Erum Arif; Akyüz, Ahmet Oğuz; Reinhard, Erik (2006-10-11)
High dynamic range images may be created by capturing multiple images of a scene with varying exposures. Images created in this manner are prone to ghosting artifacts, which appear if there is movement in the scene at the time of capture. This paper describes a novel approach to removing ghosting artifacts from high dynamic range images, without the need for explicit object detection and motion estimation. Weights are computed iteratively and then applied to pixels to determine their contribution to the fin...
Deep joint deinterlacing and denoising for single shot dual-ISO HDR reconstruction
Çoğalan, Uğur; Akyüz, Ahmet Oğuz; Department of Computer Engineering (2019)
HDR (High Dynamic Range) images have traditionally been obtained by merging multiple exposures each captured with a different exposure time. However, this approach entails longer capture times and necessitates deghosting if the captured scene contains moving objects. With the advent of modern camera sensors that can perform per-pixel exposure modulation, it is now possible to capture all of the required exposures within a single shot. The new challenge then becomes how to best combine different pixels with ...
Image dynamic range enhancement
Özyürek, Serkan; Akar, Gözde; Department of Electrical and Electronics Engineering (2011)
In this thesis, image dynamic range enhancement methods are studied in order to solve the problem of representing high dynamic range scenes with low dynamic range images. For this purpose, two main image dynamic range enhancement methods, which are high dynamic range imaging and exposure fusion, are studied. More detailed analysis of exposure fusion algorithms are carried out because the whole enhancement process in the exposure fusion is performed in low dynamic range, and they do not need any prior inform...
Automatic tests for camera performance analysis
Hasarpa, Alican; Akar, Gözde; Department of Electrical and Electronics Engineering (2018)
The camera technology is consistently improving, with high definition, smartcameras being utilized all around the world. Because of the different quality of such cameras, the camera performance analysis plays a critical role for the end users in order to determine the real difference between the available alternatives. The image quality of a camera may be assessed visually using digitally generated test patterns in a controlled environment. The main purpose of this thesis is to automate this assessment and ...
Citation Formats
M. Türe, “Image based solar position editing and relighting,” M.S. - Master of Science, Middle East Technical University, 2018.