HDR image creating algorithm

Question

Do you know any algorithm to create HDR images, like photomatix or photoshop "merge hdr" function?

Answer 1

Are you referring to Pseudo HDR (HDR look from 1 image) or HDR from few different images (Each with different Exposure)?

Usually HDR starts with Edge Preserving Smoothing operator. This allows to differentiate between the details, where we want to keep data, to flat areas, where we can compress the data.

The next step would be applying a compressing function to the data we want to compress.

The last step would be to blend the compressed data.

I would start by reading about Tone Mapping: http://en.wikipedia.org/wiki/Tone_mapping

Answer 2

Matlab has merge HDR function. If you have matlab installed, you can get source code of it in installation directory.(but you cannot use it for licensed app).

For few more details:
Open Source HDR library recommendations

Answer 3

I would suggest the HDR Toolbox which has open source (GPL v3) code and advanced alignment modes: https://github.com/banterle/HDR_Toolbox/tree/master/source_code/Generation

http://www.advancedhdrbook.com

Answer 4

I don't know what language you use, but you can always take a look at the source code for Luminance (Qtpfsgui) and see how they do it.

Remember though, that that code is copyrighted so you can't really copy & paste into a differently licensed app.