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Maniphest T5091

Strange rendering artefacts
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Authored By
lodron
Aug 13 2010, 10:59 AM
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Referenced Files
F588: Example 2 both.tif
Aug 13 2010, 11:14 AM
F587: Example 2 only one.tif
Aug 13 2010, 11:12 AM
F586: Both.tif
Aug 13 2010, 11:01 AM
F585: OnlyTopImage.tif
Aug 13 2010, 11:00 AM
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• goch
lodron

Description

Hi

I found some strange rendering artefacts in the following case:

I have two mitk::Image's with different size and spacing loaded, all with opacity = 1, default level window, default lookup table (n/a) and the default transfer function, texture interpolation is set to OFF and both are marked as visible.

So normally only the image which is at top layer should be visible (fore sure without border area when the background image is bigger than the foreground image).

At the first look that seems to be right but when i look closer (especially at dark regions with zoom) and toggle the visibility of the background image i can see some pixels which change their value. The grayvalue change is only in the Renderer visible, in the lower area where the Position/Index/Time and Pixelvalue is displayed the Pixelvalue stays the same....

I can posted some screenshots ...

Event Timeline

lodron added projects: MITK, Bugzilla.Aug 13 2010, 10:59 AM
lodron added a subscriber: lodron.

Only image which greater layer visualized

OnlyTopImage.tif191 KBDownload

lodron added a comment.Aug 13 2010, 11:01 AM

Both images visulaized, for sure opacity of both is 1

Both.tif134 KBDownload

lodron added a comment.Aug 13 2010, 11:12 AM

Here the absolute difference between two images is calculated and visualized, again opacity=1

Example 2 only one.tif142 KBDownload

lodron added a comment.Aug 13 2010, 11:14 AM

Here the difference image is at top layer with opacity = 1 and a background image is set to visible. Nothing should change since opacity = 1

Example 2 both.tif145 KBDownload

• goch added a subscriber: • goch.Aug 13 2010, 12:03 PM

if any pixel in an image has a grey value, that is lower than the lower bound of the level window it is in fact not rendered as black, but as transparent. If you happen to have an image on layer below that has a non black pixel at the same position it will show through.

You can easily observe this by loading the same image twice, setting the colour of the background image to red and changing the level window of the foreground one to a small width in the upper grey value range.

• goch added a comment.Aug 13 2010, 12:04 PM

Closing, at it is no bug, but standatd behaviour.

kislinsk changed the task status from Invalid to Spite.Jun 27 2018, 1:33 PM
kislinsk added a project: Bulk Edit.
kislinsk changed the task status from Spite to Invalid.Jun 27 2018, 1:37 PM
kislinsk removed a project: Bulk Edit.
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