Title :
Sequential image stitching for mobile panoramas
Author :
Xiong, Yingen ; Pulli, Kari
Author_Institution :
Nokia Res. Center, Palo Alto, CA, USA
Abstract :
This paper presents a sequential image stitching approach for creating high-quality panoramic images on mobile devices. In this approach, each source image in the image sequence is stitched onto the panoramic image sequentially using two operations: optimal seam finding and transition smoothing. In the seam finding process, graph cut optimization finds an optimal seam and creates labeling in the overlapping area between the current panoramic image and the current source image. The current panoramic image can be updated by merging the current source image using the labeling information. If there are visible stitching artifacts in the seam, a transition smoothing operation is performed to hide the seam and remove the stitching artifacts. In the transition smoothing process, a gradient vector field is created from the gradients of corresponding pixels in the current labeled source image to construct a Poisson equation. A composite image can be recovered from the gradient vector field by solving the Poisson equation with boundary conditions. The current panoramic image is updated by merging the composite image. The approach presents several advantages. The use of graph cut optimization guarantees finding optimal seams and avoids blurring and ghosting problems caused by objects moving between capture of input images or by spatial alignment errors. The gradient domain transition smoothing process reduces color differences and further improves image quality. The sequential panorama stitching procedure enables us to produce high resolution panoramic images with limited memory resources. The approach is implemented and it produces high quality panoramic images on mobile devices. It shows good performance for both indoor and outdoor scenes.
Keywords :
Poisson equation; boundary-value problems; gradient methods; graph theory; image colour analysis; image resolution; image restoration; image sequences; mobile computing; mobile handsets; optimisation; Poisson equation; boundary conditions; color differences; current source image; gradient domain transition smoothing process; gradient vector field; graph cut optimization; high resolution panoramic images; high-quality panoramic images; image blurring; image ghosting; image quality; image sequence; limited memory resources; mobile devices; mobile panoramas; optimal seam finding; seam finding process; sequential image stitching; sequential panorama stitching procedure; spatial alignment errors; stitching artifacts; transition smoothing operation; Boundary conditions; Color; Image quality; Image sequences; Labeling; Merging; Pixel; Poisson equations; Smoothing methods; Spatial resolution; Image stitching; graph cut optimization; image blending; mobile computational photography; mobile image processing; mobile panorama; multigrid solver; optimal seam finding; panorama stitching; transition smoothing;
Conference_Titel :
Information, Communications and Signal Processing, 2009. ICICS 2009. 7th International Conference on
Conference_Location :
Macau
Print_ISBN :
978-1-4244-4656-8
Electronic_ISBN :
978-1-4244-4657-5
DOI :
10.1109/ICICS.2009.5397590