Changes for page 2. Image pre-processing with Nutil Transform
Last modified by puchades on 2021/12/07 10:37
Summary
-
Page properties (2 modified, 0 added, 0 removed)
Details
- Page properties
-
- Title
-
... ... @@ -1,1 +1,1 @@ 1 -2. Image pre -processingwith Nutil Transform1 +2. Image preparation with Nutil Transform - Content
-
... ... @@ -1,24 +1,27 @@ 1 - **The//Transform// feature in the //Nutil// software **enables **imagerotation, renaming, resizing and mirroring,** and is used toprepareimageseriesfor atlas alignment with QuickNII and segmentationwithilastik. It should be noted that QuickNII and ilastikhave different input image size requirements. In addition, it is important that the input imagesfollow the standard namingconvention described below..1 +== Image pre-processing with Nutil Transform == 2 2 3 ->(% style="color:#27ae60" %)The //QuickNII// and //ilastik// software have different input image size requirements. It is also important that the input images follow the prescribed naming convention. 4 4 5 - ==(%style="color:#c0392b"%)Input requirements(%%)==4 +**The //Transform// feature in the //Nutil// software **enables **image rotation, renaming, resizing and mirroring** and is used to prepare the image series for //QuickNII //alignment and //ilastik //segmentation. 6 6 7 - For //QuickNII,// the input requirementsaredescribed inin Puchades etal., 2019. Tosummarise,images should bein 24-bit PNG orJPEG format, and can beloaded upto a resolutionof16 megapixels (e.g.4000x4000or5000x3000 pixels).However//QuickNII// doesnot benefit from image resolutionsexceeding the resolution ofhe monitorin use.For a standard FullHD or WUXGA display (1920x1080 or 1920x1200 pixels) the useful imageareaisapproximately 1500x1000 pixels. Usinga similar resolution ensuresoptimalimage-loadingperformance.6 +>The image input size requirements for the //QuickNII// and //ilastik// software differ. Naming convention of files is important. 8 8 9 -For //ilastik// (Borg et al.2019) images are downscaled in order to enable efficient processing. The pixel classification algorithm relies on input from manual user annotations of the training images, and the features ‒ intensity, edge and/or texture ‒ of the image pixels. The resizing factor is determined by trial and error, with a test run performed with //ilastik// on images of different sizes to determine the optimal resolution for segmentation. As an example, in Yates et al., 2019, the images were downscaled by a factor of 0.1 and 0.05 for cellular features and Alzheimer's plaques respectively (factor applies to the image width here). 8 +For //QuickNII,// the input requirements described in (Puchades et al., 2019) are: 9 +24-bit PNG and JPEG. Images can be loaded up to the resolution of 16 megapixels (e.g.4000x4000 or 5000x3000 pixels), however QuickNII does not benefit from image resolutions exceeding the resolution of the monitor in use. For a standard FullHD or WUXGA display 10 +(1920x1080 or 1920x1200 pixels) the useful image area is approximately 1500x1000 pixels,using a similar resolution ensures optimal image-loading performance. 10 10 11 - ===(%style="color:#c0392b"%)Naming convention(%%)===12 +For //ilastik// (Borg et al.2019), the resizing was performed in order to enable efficient processing. To clarify, the pixel classification algorithm relies on input from manual user annotations of training images, and the features ‒ intensity, edge and/or texture ‒ of the image pixels. In practice, a test run was performed with //ilastik// on images of different sizes to find the optimal resolution for segmentation, with a final resize factor of e.g 0.1 for cellular features, and a factor of 0.05 for series with larger features like Alzheimer plaques. 12 12 13 - ForQUINTanalysis, Nutil Quantifier quantifies objects extracted fromsegmentations and registersthem to regions defined bycustomised atlas maps. To match segmentations and corresponding atlas maps together, Nutil Quantifier reliesona unique ID in the file name of both files.The ID should be unique to the particular brain section and in the format:sXXX.., with XXX.. representing the section number. The section number should reflect the serial order and spacing of the sections (e.g. s002, s006, s010 for every 4^^th^^ section starting with section 2).14 +=== Naming convention: === 14 14 16 +For running the QUINT analysis the segmentation files and the customized atlas maps need to match and therefore the segmentation files should follow the same naming format.The file name that correspond to a particular section must contain a unique ID in the format: sXXX.., with XXX.. representing the section number. The section number should reflect the serial order and spacing of the sections (e.g. s002, s006, s010 for every 4^^th^^ section starting with section 2). 17 + 15 15 Example: tg2345_MMSH_s001_segmentation.png 16 16 17 17 (It is fine to include a string of letters and numbers followed by the unique ID). 18 18 19 19 20 -=== (% style="color:#c0392b" %)Running the transformation(%%)===23 +=== Running the transformation === 21 21 22 -Consult the Nutil user manual for detailed procedure (lin cludedintheNutil package availablefor downloadatNitrc.org)25 +Consult the Nutil user manual for detailed procedure (link to Manual on Nitrc.org) 23 23 24 24 [[image:Figure_2_v3.jpg]]