# What filters would I use to mimic these changes using macOS Preview

**URL:** <https://discourse.itk.org/t/what-filters-would-i-use-to-mimic-these-changes-using-macos-preview/4296>\
**Category:** Uncategorized\
**Created:** [July 27, 2021, 9:52pm UTC](https://discourse.itk.org/t/what-filters-would-i-use-to-mimic-these-changes-using-macos-preview/4296 "2021-07-27T21:52:07Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![imikejackson](https://discourse.itk.org/user_avatar/discourse.itk.org/imikejackson/32/35_2.png) [@imikejackson](https://discourse.itk.org/u/imikejackson)\
**Post date:** [July 27, 2021, 9:52pm UTC](https://discourse.itk.org/t/what-filters-would-i-use-to-mimic-these-changes-using-macos-preview/4296/1 "2021-07-27T21:52:07Z")

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![Screen Shot 2021-07-27 at 17.47.52](https://discourse.itk.org/uploads/default/original/2X/4/4aefffe1d1810523f2af76f1888e72a529e8b0f7.png)

I would like to perform the same types of image operations that I performed in macOS Preview.app as shown in the attached image in ITK (specifically in python). Does ITK have filters that would mimic these changes?

I moved the “Contrast” slider all the way to the right.  
And I adjusted the “middle” carrot thing just under the histogram to the right a bit.

Thanks  
Mike Jackson

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**Author:** ![dzenanz](https://discourse.itk.org/user_avatar/discourse.itk.org/dzenanz/32/1093_2.png) [@dzenanz](https://discourse.itk.org/u/dzenanz)\
**Post date:** [August 3, 2021, 7:18pm UTC](https://discourse.itk.org/t/what-filters-would-i-use-to-mimic-these-changes-using-macos-preview/4296/2 "2021-08-03T19:18:43Z")

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Here is some description of [contrast](https://docs.opencv.org/3.4/d3/dc1/tutorial_basic_linear_transform.html) does. It could be implemented using ITK’s [ShiftScaleImageFilter](https://itk.org/Doxygen/html/classitk_1_1ShiftScaleImageFilter.html).

I am not familiar with macOS Preview.app, so cannot suggest a way to implement it’s histogram adjustment controls.