Take a psd and export all the layers into separate image files without using Photoshop

There is a tool from Telegraphics called PSDParse that should do the trick.

psd2png.exe -w Filename.psd

usage: psd2png.exe [options] psdfile...
-h, --help show this help
-v, --verbose print more information
-q, --quiet work silently
-w, --writepng write PNG files of each raster layer (and merged composite)
-d, --pngdir dir put PNGs in directory (implies --writepng)
-m, --makedirs create subdirectory for PNG if layer name contains \'s
-l, --list write an 'asset list' of layer sizes and positions
-s, --split write each composite channel to individual (grey scale) PNG

Here's a link to the version I used, or you can go to the website for the latest version for your operating system.

http://www.telegraphics.com.au/sw/files/psdparse-1.7b1-win.zip

If you don't want to install any plugin, do this using GIMP (open source tool):

1. Select the layer and copy Ctrl+C or Edit > Copy
2. Then Select > File > Create > From Clipboard, this creates a new document from the copied layer, or you can just make the layer you want the only thing visible.
3. Then select > File > Save As... then go down to "Select File Type (By Extension)"
4. In the box where it says "All images select that box and go down to "PNG image (*.png)"

There's a plugin for that: Export Layers as PNG.

It adds an entry to the File menu, Export layers -> as png.

Go to "File" menu in Photoshop (trial or free, no matter)

Now go to "Export" submenu and select "Export layers to files".

In the opened dialog, choose PNG as file type and browse for destination folder.