topic File Size Doubled After Compressing and Reprojecting Drone Image in ArcGIS Pro in ArcGIS Pro Questions

File Size Doubled After Compressing and Reprojecting Drone Image in ArcGIS Pro

logri-sl — Tue, 03 Feb 2026 05:31:04 GMT

Problem Summary

I'm trying to compress a drone raster image while converting it from EPSG:32628 (WGS 84 / UTM Zone 28N) to EPSG:4326 (WGS 84 Geographic) in ArcGIS Pro, but the output file size is double the original file size instead of being smaller.

My Workflow

I used the Copy Raster tool with the following settings:

Input Raster: Freetown drone image (EPSG:32628)
Output Coordinate System: EPSG:4326 (WGS 84)
Output Format: TIFF (.tif)
Pixel Type: 8-bit unsigned
NoData Value: 0
Compression Type: JPEG
Compression Quality: 75
Build Pyramids: Checked
Pyramid Compression: JPEG
Resampling Technique: Bilinear

Expected Result

A compressed image with significantly reduced file size (50-80% reduction) in EPSG:4326.

Actual Result

The output file size is approximately 2x the original file size.

Questions

What might be causing the file size to increase instead of decrease?
Could the CRS conversion from UTM (meters) to Geographic (degrees) be increasing pixel count?
Are internal pyramids adding significantly to the file size?
Is there a better workflow to compress AND reproject simultaneously without increasing file size?
Should I separate the reprojection and compression into two separate steps?

Environment

Software: ArcGIS Pro
Input Image: Drone imagery (RGB)
Original CRS: EPSG:32628
Target CRS: EPSG:4326

What I've Tried

Using Copy Raster tool with JPEG compression
Setting compression quality to 75
Building pyramids with JPEG compression

Any advice on the proper workflow or settings to achieve both compression and CRS conversion without increasing file size would be greatly appreciated!

Re: File Size Doubled After Compressing and Reprojecting Drone Image in ArcGIS Pro

tikola — Wed, 04 Feb 2026 11:57:44 GMT

I see at least two possibilites:

When square file is reprojected image gets tilted and truly amount of rows and columns increase. Check input and output row and column amount and do you get black triangels in image corners. So is your image size (row&column amount) truly growing after reprojection?
Another option - input TIF had some compression that was better than jpeg you are now using. TIF can contain so many different things that there well might be some jp2 or some other stronger compression than the one you now use. However that would most likely be something way bigger that 50-80 %

Re: File Size Doubled After Compressing and Reprojecting Drone Image in ArcGIS Pro

JudithWammack — Thu, 26 Mar 2026 13:47:13 GMT

@logri-sl have you figure out a solution on this? I am running into the same issues with file size doubling.

Re: File Size Doubled After Compressing and Reprojecting Drone Image in ArcGIS Pro

logri-sl — Thu, 26 Mar 2026 16:52:49 GMT

No, unfortunately, I wasn't able to resolve this issue. Good luck! I hope you're able to do so!

Re: File Size Doubled After Compressing and Reprojecting Drone Image in ArcGIS Pro

JudithWammack — Thu, 26 Mar 2026 20:47:54 GMT

@logri-sl Have you worked with the Cloud Raster Format (CRF) before? We recently came across this format and found that it significantly reduces file size while maintaining imager quality.

Our current workflow involves taking 536 aerial TIFF images, converting them into a more compressed format, reprojecting them, and then publishing them to create a cache. So far, using CRF has produced smaller file sizes without compromising image quality.

Do you think this approach would work for your needs?

For reference, the following documentation provides an overview of CRF workflows and their capabilities:
https://doc.arcgis.com/en/imagery/workflows/standard-workflow/preparing-your-data/data-sources-and-formats.htm