Median Cut

Motion Blur


Diffuse SH


TMO: Drago

TMO: EriKate

TMO: ExpLog

TMO: Greg

TMO: Scan

Filter Plugins a la carte

Picturenaut's ability to run HDR Shop Plugins natively extends it's capabilities tremendously, because Francesco Banterle has already created complete set of high dynamic range filters and tools, that plug right in.


All you have to do is download Banty's Toolkit and extract all the plugins into the Picturenaut\plug-ins\hdrshop folder. Then they will show up in Picturenaut in the Filters menu, and are ready to be fired on any image.

What's included in Banty's Toolkit?

A great variety of tools, from additional tone mapping operators to analytical functions to creating synthetic HDR images from scratch. The full toolkit consists of 14 plugins all together. In fact, it is the most advanced collection of HDR Shop plugins you will find anywhere.

Browse through the menu on the left to see all plugins documented one by one. It is based off a mirror of Banty's own release notes, reformatted for better readability and restructured for quicker access. All content is copyright by Francesco Banterle, the example images "RNL" and "Grace Cathedral" are property of Paul Debevec.


It's a plug-in which calibrates and calculates light sources in an HDRI using the algorithm of Oguz:: "Color appearance in high-dynamic-range imaging" by Ahmet Og˘uz Akyüz and Erik Reinhard. Journal of Electronic Imaging 15(3), 1 (Jul–Sep 2006).


It's a plug-in which applies the bilateral filter to an image. This filter smoothes an image, but keeps sharp edges. This plug-in can apply a non-approximated version only on the luminance channel, and an approximated version (two 1D bilateral filtering applications) on all channels.

HDRI by Paul Debevec.

Bilateral Filtered Image

Difference of the two images


It's a plug-in which scales the exposoure of a range of pixel values to generate an HDRI from a 24bit image (LDRI). It gets as input the range of value to change, and the maximum intensity allowed, wich'll be interpolated linearly.

Clamped RNL probe in false color

Fake HDRI applied to a clamped RNL in false color


It's a plug-in which applies to images a choise between Maximum, Median, and Minimum filter. It gets as input the size of kernel.

HDRI RNL di Paul Debevec.

Maximum filter. kernel = 8

Median filter, kernel = 8

Minimum filter, kernel = 8

Median Cut

It's a plug-in which generates directional lights from an HDRI (panoramic format). The algorithm is based on the paper "A Median Cut Algorithm for Light Probe Sampling" by Paul Debevec of Siggraph 2005. The plug-in creates a .txt file with light's parameters. Now this plugin creates a MaxScript that makes possible to import lights in 3DStudioMAX (raytrace shadow or shadowmap).

HDRI RNL by Paul Debevec.

256 Directional Lighs.

Median Cut Rendering: 260sec.
with 256 lights. AntiAliasing 8x

Monte Carlo: 551sec.
with 256 samples. AntiAliasing 8x

Notes on usage:

1) There's two checkbox for the settings of the Median Cut algorithmt:

  • The first "Average (else lumiance)": if it's activated the average color is used for computation, else it uses luminance.
  • The second "KD-Tree split (else longest dimension)": if it's activated a KD-Tree like scheme is used for splitting regions, else it's selected by the longest dimension.

2) MedianCut creates directional lights in various file formats:

  • Raw Format: Creates a file called "lights.txt". Here an example of the lines in the file:
Dir: 0.097656 0.995185 0.008410
Pow: 1737.421387 883.334839 885.104065
Where "Dir" is 3D unit vector, the direction of light. "Pow" is the intesity of the light in RGB color space.

  • 3D Studio MAX: it creates a MaxScript in which the lights are described. Filename is "".
  • Maya: it creates a MEL script in which the lights are described. Filename is "lights.mel".
  • Radiance: it creates a .rad file in which the lights are described. Filename is "lights.rad".

3) Exporting options:

  • Shadow maps/Raytrace: if checked it will creates lights which use shadow map for the shadowing stuff, else raytracing.
  • Luminance scale: it's a value used to scale final color.
  • Hemisphere radius: it's the radius of hemisphere for the generated lights (this option is valid only if you want to export for Maya or 3D Studio MAX).
  • Divide Power by PI/size: if checked it will scale final color using as weight the value PI/size, where size is the number of pixel of image.

Gaussian Motion Blur

It's a plug-in which applies gaussian motion blur to the HDRI. It gets as input the angle of motion, the variance of gaussian function, and the size of filter.

HDRI RNL by Paul Debevec.

Motion blur with 45° angle


It's a plug-in which applies a custom convolution filter, loaded from a text file. An example of .txt filter file:
norma: 0.0
size: 3
-1.0 -1.0 -1.0
-1.0 9.0 -1.0
-1.0 -1.0 -1.0

The parameter norma is a manual normalization value, if we want an automatic normalization we must set this value to 0.0.
The parameter size is the size of convolution kernel. After this value we must insert the filter matrix. The number of values is a square of size. For example, a size 3 kernel needs a 3 by 3 matrix here.

Diffuse SH

It's a plug-in which calculates diffuse convolution of an HDRI (panoramic format). It speeds-up complexity to O(n) against O(n^2) of the naive algorithm implemented in HDR Shop 1.0.3. The algorithm is based on the paper "An Efficient Representation for Irradiance Environment Maps" by Ravi Ramamoorthi and Pat Hanrahan of Siggraph 2001. In the example the computational time is less than a second with an 512x256 HDRI, against the six hours expected using the naive algorithm. This plugin creates a ASCII file with the coefficients of Spherical Harmonics calculated.

HDRI RNL by Paul Debevec.

Diffuse Lighting Map based on the RNL probe.


It's a plug-in which creates a sky envorinmental map. There are four available model of sky: CIE Standard Overcast Sky, CIE Clear Sky, CIE Partially Cloudy, Preetham Sky: "A practical analytic model for daylight" byA. J. Preetham, Peter Shirley and Brian Smits. Siggraph 1999.

CIE Overcast Sky

CIE Clear Sky

CIE Cloudy Sky

Preetham Sky


It's a plug-in which applies the Drago tone mapping operator: "Adaptive Logarithmic Mapping For Displaying High Contrast Scenes" by F. Drago, K.  Myszkowski, and N. Chiba., 2003, Eurographics Symposium on Rendering.

HDRI by Paul Debevec.

Drago TMO


It's a plug-in which applies the Erik Reinhard and Kate Devling tone mapping operator: "Dynamic Range Reduction Inspired by Photoreceptor Physiology" by Erik Reinhard and Kate Devlin. IEEE Transactions on Visualization and Computer Graphics, 11(1), Jan/Feb 2005.

HDRI by Paul Debevec

EriKate TMO


It's a plug-in which applies the Logarithmic or Exponential tone mapping operator.




It's a plug-in which applies the Greg Ward tone mapping operator: "A Contrast-Based Scalefactor for Luminance Display" by Greg Ward. Graphics Gems IV, Edited by Paul Heckbert, Academic Press 1994.

HDRI by Paul Debevec

Greg TMO


It's a plug-in which applies a propretary tone mapping operator. It was designed for range compression of HDRIs, but it can enhance normal images.

HDRI by Paul Debevec.

Scan TMO