Image Trace not tracing large files

[gabrielamadeus]

I'm having difficulty with Image Trace. I've used it succesfully for years but for this project it just seems broken. 

Macbook Pro, High Sierra, 10.13.6

Illustrator 24.2

I've got a file that's a black and white line drawing of rivers in Oregon. If I take a small crop of it I can trace it almost perfectly: 

But when I trace the full image like so: 

I get these terribly innaccurate results: 

   

Any solutions? I can't seem to find any other record of this issue arising.

Here's the file if you want to experiment: https://drive.google.com/file/d/1txfHNZ5z36El8RG8iiNxuOc4pie6u8zP/view?usp=sharing

Thanks for your time!

[@mj]

Hi gabrielamadeus,

It seems you might be hitting a resource ceiling.

You can check this using Activity Monitor on your Mac.

Here are some things I did to reduce the file in Photoshop.

Converted from RGB to Grayscale and cropped away unneeded white space. File size reduction from 162.5Mb > 48.5Mb

Converted from Grayscale to Bitmap and file size dropped to 6.18Mb

Here's a handy resource from fellow ACP Monika Gause on optomizing results.

https://helpx.adobe.com/illustrator/using/image-trace-results-optimization.html#Limitations

I can send you the trace result too if you wish

Good luck

.mj