Next: `Edit' menu Up: Reference Function List (by Previous: `File' menu

Subsections

`Create' menu


Assemble HDR From Image Sequence... [Ctrl+Alt+A]

See this online tutorial for more detailed instructions. HDR Shop v3.0 allows you to create HDR images from any LDR, HDR or RAW format using either image pixel values or file metadata to guide the assembly.

Basic procedure:

Activate the tool from the menu or keyboard.

Image Assemble

If your sequence contains exif information and you do not wish to use this metadata, uncheck the 'Use EXIF' box. Images can be half-sized on loading for speed of processing by checking the 'Half-size' box. Load a sequence of images by dragging or using the 'Open Images' button. The tool will calculate the relative and absolute stops and scales for the images in the sequence using either the EXIF metadata or the actual pixel values. These values can be hand edited in the worksheet, or changed by choosing one of the values in the 'Change F-stop increments' box.


Calibrate Camera Curve... [Ctrl+Alt+C]

See this online tutorial for more detailed instructions. A digital camera sensor typically has a near-linear response to light within its limits, but in an effort to make the images relate to photographic film images, the linear values are scaled in the camera according to some non-linear mapping. When the LDR images are loaded in a typical image viewer it automatically applies a fixed reverse response function (gamma correction) in order to make the values appear linear on whatever display is being used. The camera curve calibration tool allows you to recover the non-linear mapping ( camera response function) that was applied, using a sequence of images of a scene taken from a fixed viewpoint, requiring only that you specify the relative exposure differences between the images in the sequence.

Basic procedure:

Activate the tool from the menu or keyboard.

Image CamCalib1

Activate the tool from the menu. Drag your sequence of images on to the window. The tool automatically sorts the sequence into darkest-to-brightest order. Next set the scale increments between the images. The tool works best for shots taken exactly 1 (or less) stop(s) apart, although it can handle larger differences and even non-uniform differences, so long as you know those differences. The scale differences can also be specified per channel if so required. Choose a smoothing factor or accept the default (moderate smoothing) and click 'Generate'. The tool will gather samples across the image sequence and use these to find the response function. The recovered curves are displayed in the output window:

Image CamCalib2

The window allows the curve values to be inspected. Further smoothing can be applied manually to the curves. You can now either save out the 3 rgb curves or choose r, g, or b individually if you feel one is a better representation than the others. Curves are saved out in a Matlab-style '*.m' file.


Spherical Harmonics... [Ctrl+Alt+H]

Spherical Harmonic (SH) images can be used to calculate the lighting on a 3D model from area light sources in real time. HDR Shop allows you to quickly create any SH image mapped into various panoramic formats. The dialog is shown below:

Image SHDlg

Available panoramic formats (See this online tutorial for more information about these formats):


Panoramic Direction Table... [Ctrl+Alt+P]

Create an image plot of unit-length 3D surface normal directions in one of various panoramic formats. A panoramic direction table in the 'Angular Map' format is shown below:

Image PanoramicDirection

The pixel values represent these 3D directions such that red, blue and green correspond to x, y and z vector components of the 3D normal. Note that we use a right-handed coordinate system such the directions +x = right, +y = up and +z = viewer-to-screen. Simply Scale the blue channel by -1 if you require a left-handed coordinate frame.

Available panoramic formats (See this online tutorial for more information about these formats):


Macbeth Chart... [Ctrl+Alt+M]

Create a small $ 6 \times 4$ pixel image representation of a Gretag-Macbeth color chart with reference linear values of a desired color space. Use these small images in conjunction with your own camera's image of a Macbeth chart to compute the color matrix that will map your camera's images into that particular color space.

Available reference color space charts:
See this online tutorial for example usage.

Next: `Edit' menu Up: Reference Function List (by Previous: `File' menu
Generated by Bruce Lamond on 2009-03-16