# Reduce image size and filter?
**URL:** https://discourse.julialang.org/t/reduce-image-size-and-filter/105926
**Category:** Visualization
**Created:** [November 8, 2023, 4:50am UTC](https://discourse.julialang.org/t/reduce-image-size-and-filter/105926 "2023-11-08T04:50:17Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@rmfritz](https://discourse.julialang.org/u/rmfritz)
#### Post date: [November 8, 2023, 4:50am UTC](https://discourse.julialang.org/t/reduce-image-size-and-filter/105926/1 "2023-11-08T04:50:17Z")
I’m working with a physically-based rendering image (HDR, units of radiance or irradiance in an RGB model) and I would like to create an unsharp mask from it, reducing the size and applying a box filter. I am not seeing an obvious way of doing this. Am I missing something? Or should I just proceed to write my own? (Sigh.) I do have an example to work from, but these things are fiddly and it might take some effort.
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### Author:  [@GunnarFarneback](https://discourse.julialang.org/u/GunnarFarneback)
#### Post date: [November 8, 2023, 8:16am UTC](https://discourse.julialang.org/t/reduce-image-size-and-filter/105926/2 "2023-11-08T08:16:13Z")
I would expect that functions from the Images package should be able to do this, see e.g. [ImageFiltering.jl · ImageFiltering](https://juliaimages.org/ImageFiltering.jl/stable/) and [Cropping, Resizing and Rescaling · JuliaImages](https://juliaimages.org/latest/examples/spatial_transformation/SpatialTransformations/).
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### Author:  [@Eben60](https://discourse.julialang.org/u/Eben60)
#### Post date: [November 8, 2023, 8:34am UTC](https://discourse.julialang.org/t/reduce-image-size-and-filter/105926/3 "2023-11-08T08:34:28Z")
As usually, there would be more that one package to do something in Julia. One of these (which I never used) is the [OpenCV.jl](https://docs.opencv.org/4.x/d8/da4/tutorial_julia.html) Julia wrapper.
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### Author:  [@rmfritz](https://discourse.julialang.org/u/rmfritz)
#### Post date: [November 8, 2023, 9:52pm UTC](https://discourse.julialang.org/t/reduce-image-size-and-filter/105926/5 "2023-11-08T21:52:39Z")
Thanks. Unfortunately, with the exception of ImageFiltering, most of those libraries do not work with physical units. There are hints that OpenCV does (at least, it offers HDR) but I can’t quickly find out for sure.
Thanks for the replies, anyway.