Load images for HDR blending

Load 3 or 5 images of an exposure series into GIMP for HDR blending.

This is a helper script aimed at automating the loading procedure of the GIMP HDR Workflow described at http://www.instructables.com/id/HDR-photos-with-the-GIMP/.

Here's a quick overview of the HDR workflow:

• start with the the "center" image of an exposure series - this is the background image
• add the "dark" image(s) of the series as layers
• add a layer mask
• paste the desaturated dark image to the layer mask, thus letting the "bright" parts of the dark image through while blocking the "dark" parts
• add the "bright" image(s) of the exposure series
•  add a layer mask
• paste the desaturated *inverted* bright image to the mask, thus composing the "darker" areas of the bright image into the picture while discarding the brighter areas
• adjust by changing the brightness levels of the layer masks

The script automates all but the last step. After installing you'll get two new menu entries in the "File" pulldown menu: 

       "Load images for HDR blending (3 images)..."

       "Load images for HDR blending (5 images)..."

The script assumes that you already loaded the "middle" image. Clicking the menu entry will pop up a dialog which lets you load the dark and bright picture(s). The script currently only supports 3 or 5 images in a series since that's what I need :) let me know if your use case differs.

After the images have been added in the dialog the script will generate corresponding layers, paste the image contents, generate layer masks, and fill the masks accordingly. 

You can adjust the HDR effects of each layer by playing with the layer's opacity (which lets you play with the settings without actually changing anything in the layers) or by editing  the layer mask's brightness/contrast settings (which doesn't).

Adjusting a layer mask's brightness/contrast is as easy as 

• clicking the layer
• selecting "Colours -> Brightness/Contrast"

since all the newly created layers will be in "mask editing" mode after the script finished.

Revision History

• v1.1 Feb 19 2011 - Added gaussian blur option inspired by J.D. Smith's great "exposure blend" script.
• v1.0 Feb 07 2011 - Initial version.

Have fun using this and let me know what you think.                                               -- thilo, feb. 10, 2011