Reducing metal artifacts by restricting negative pixels

Reducing Artifacts in Volume Rendering by Higher Order Integration

In this paper we show that approximation errors predominate the artifacts that can be seen. A new integration scheme for solving the volume rendering equation is presented that leads to artifact free images and accurate resolutions down to voxel size. We propose a method for acquiring additional sample points needed for higher order integration very efficiently in order to allow the competing g...

Towards characterizing and reducing artifacts caused by varying projection truncation

Metal Artifacts in Computed Tomography

Karin Andersson (2018): Metal Artifacts in Computed Tomography – impact of reduction methods on image quality and radiotherapy treatment planning. Örebro Studies in Medicine 172. Degradation of image quality by metal artifacts is a common problem in computed tomography (CT) imaging, which can limit the diagnostic value of a CT examination and also introduce inaccuracies in radiotherapy (RT) tre...

Reducing Blocking Artifacts in Compressed Images

Transform coding is one of the most popular image compression techniques. However in these transformations, the image is divided into sub-blocks and each block in transformed individually. This introduces boundaries called blocking artifacts along the edges of these blocks. In this paper, we have discussed a spatial filtering method for reducing the blocking artifacts in transformed images. We ...

Reducing artifacts from varying projection truncations

We study samples with full and partial occlusion causing streak artifacts, and propose two modifications of filtered backprojection for artifact removal. Data is obtained by the SPring-8 synchrotron using a monochromatic parallel-beam scan [1]. Thresholding in the sinogram segments the metal, resulting in edges on which we apply 1) a smooth transition, or 2) a Dirichlet boundary condition.