How can I resize an extremely large image if normal editors won't open it?

Asked 10/17/2014

129 views

2 answers

I have a very large image (about 18,984 × 28,591 pixels) that Paint and browser-based editors like Pixlr won’t open. What’s the best way to downsize or convert an image this large on a laptop, especially if memory is limited?

software workflow imagemagick jpeg image-resizing

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

12y ago

2 Answers

I used ImageMagick on Ubuntu to resize those big pictures.

convert -resize 10% source.jpg dest.jpg

It took awhile, but worked with 1 GByte of RAM, the tool created a 4.7 Gbyte swap-like file for itself.

More information is on AskUbuntu.

Originally by user24785. Source · Licensed CC BY-SA 4.0

user24785

12y ago

AI Answer

Generated from our catalog & community — verify before relying on it.

Use a tool made for large-image processing rather than a basic editor. Command-line utilities are often the most reliable because they can handle big files with less RAM.

Two options mentioned:

ImageMagick: can resize very large images, though it may be slow and use disk swap if RAM is limited. Example: convert -resize 10% source.jpg dest.jpg
For JPEG specifically: djpeg can scale the image during decoding, which is more memory-efficient than fully opening it first. Example: djpeg -scale 1/8 huge_image.jpg > downscaled.ppm

On Windows, a simple batch resizer like Picture Resizer may also help, though its performance with extremely large files can vary.

If your laptop struggles, start with a strong downscale factor (such as 10% or 1/8), save the smaller file, then open that in your normal editor.

How can I resize an extremely large image if normal editors won't open it?

2 Answers

Your Answer

Related Questions