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Alright, so I've been looking around on this site on how to open a big PNG image. The question I found was about a 10M png. Xee apparently did the job.

So, I downloaded Xee for my 60M file, but it crashes. So does iPhoto, Pixelmator and previewer. In the Pixelmator and Xee case, I actually had to kill the computer, and restart it. It crashed so 'hard' I couldn't get it to respond again.

How do I open this file? (and zoom it)

Specs:

newly acquired macbook pro: 4gb memory, 2.3ghz i7
58M png image
approx: 15000x30000 pixels
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2 Answers 2

up vote 1 down vote accepted

I’m afraid I don’t have a solution for you. I checked and could not find anything that is guaranteed to work because this scenarios is rare enough that it just doesn’t get mentioned enough in web pages to register on search engines.

What I can do is to explain your predicament.

The image may be 58MB on disk, but PNG is a compressed format, so to display it, the system has to decompress it in memory. A 15000x30000 image (which is huge) requires 429MB to display if it is black-and-white! If it is true-color (32-bit), then it will require 1.68GB of RAM to store.

The aforementioned 10MB image may have been 10MB on disk, but only requires 381MB of RAM to decompress (10000×10000×4Bpp = 381MB). Yours is 4.5x larger.

While you have enough total RAM, you would need to find a program that is designed to use that much memory, and unfortunately most just aren’t capable of it due to various factors. For example, even if a program uses 32-bit or even 64-bit pointers, they may uses (image, file, etc.) libraries that use smaller ones, so at some point it ends up crashing.

Graphics-editors (like Photoshop) are most likely to be able to open the file because they usually use their own libraries and are deigned to support extremely large, memory-demanding graphics files.

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sounds like he needs Gimp and 2gb of SwapSpace, I'm unsure of how setting those things up on a Mac would work. Either way it would operate very slowly. –  u8sand Nov 25 '12 at 22:40
    
Thanks for the answer. It helped me, even though it didn't conclude to the answer. I added my own answer how I fixed it. –  Topener Nov 26 '12 at 9:59

Thanks to Synetech's answer, and help from a friend, I figured it out using Photoshop.

But, starting up photoshop and opening the image in it didn't work either. What I had to do was go into performance settings in photoshop, and increase the amount of memory to be used. The standard 70% wasn't sufficient so I had to use more.

The approx 3.2GB worked fine, and I was able to actually zoom in to the image just fine.

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