# How to place seed widget exactly on the image but not above it?

**URL:** https://discourse.vtk.org/t/how-to-place-seed-widget-exactly-on-the-image-but-not-above-it/8662
**Category:** Support
**Created:** [June 4, 2022, 3:26pm UTC](https://discourse.vtk.org/t/how-to-place-seed-widget-exactly-on-the-image-but-not-above-it/8662 "2022-06-04T15:26:51Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![xxyyy159](https://discourse.vtk.org/user_avatar/discourse.vtk.org/xxyyy159/32/4528_2.png) [@xxyyy159](https://discourse.vtk.org/u/xxyyy159)
#### Post date: [June 4, 2022, 3:26pm UTC](https://discourse.vtk.org/t/how-to-place-seed-widget-exactly-on-the-image-but-not-above-it/8662/1 "2022-06-04T15:26:51Z")

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Hi, I want to select some points on image. So I implement the seed widget to help me select the points I want. But I found out the seed was placed above the image not on the image. Some images below showing the issue.

The seed widget I placed should have been on the image.  
 ![image](https://discourse.vtk.org/uploads/default/original/2X/3/3cc61f5b06ee423df3ef0c7ec7841f9e4248992f.png)  
But when I turn the camera around, they are above the image.  
 ![image](https://discourse.vtk.org/uploads/default/original/2X/c/cc3275dc1da80e892e6988e8a1be078f59612b9f.png)

How can I solve this problem?  
Or is there some methods to select point from an image?

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### Author: ![mau\_igna\_06](https://discourse.vtk.org/user_avatar/discourse.vtk.org/mau_igna_06/32/8064_2.png) [@mau\_igna\_06](https://discourse.vtk.org/u/mau_igna_06)
#### Post date: [June 5, 2022, 1:07pm UTC](https://discourse.vtk.org/t/how-to-place-seed-widget-exactly-on-the-image-but-not-above-it/8662/2 "2022-06-05T13:07:07Z")

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I guess you are transforming the sliceView to move when you move a slider that controls the current slice if this it’s a ct, otherwise if it’s an xray your matrix RAStodisplayXY transform must be not correctly defined. That’s my belief

Mauro

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### Author: ![xxyyy159](https://discourse.vtk.org/user_avatar/discourse.vtk.org/xxyyy159/32/4528_2.png) [@xxyyy159](https://discourse.vtk.org/u/xxyyy159)
#### Post date: [June 5, 2022, 2:54pm UTC](https://discourse.vtk.org/t/how-to-place-seed-widget-exactly-on-the-image-but-not-above-it/8662/3 "2022-06-05T14:54:10Z")

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Thanks for your reply.  
Actually I want to add a seed to the pixel selected.  
So the world position of the seed can tell me the location of the pixel in an 3d image date.  
Now I find a new twist: replacing the drifted position with the slice number(i.e., if I set slice orientation to XZ, I just replace the pos[1] with the slice currently showing ).