Hdr Class Reference

Inheritance diagram for Hdr:

Data Structures
class	Handle

Public Member Functions
	Hdr ()
	Constructs an HDR processing object.
void	Dispose ()
	Releases all resources.
void	EstimateResponseCurve (IEnumerable< Image > images)
	Estimates the Camera Response Curve (CRC) from a set of input images.
Image	Process (IEnumerable< Image > images)
	Generates an HDR image from the specified input images.

Properties
HdrAlgorithm	Algorithm [get]
	Returns the HDR algorithm used by this object.
ResponseCurve	ResponseCurve [get, set]

Detailed Description

Performs High Dynamic Range (HDR) image reconstruction.

This class provides functionality to generate a High Dynamic Range (HDR) image from a set of input images captured with different exposure settings. The input images are expected to depict the same scene while varying exactly one parameter: either the exposure time OR the gain.

Internally, the HDR reconstruction is performed using the Debevec algorithm. A key part of this process is determining the Camera Response Curve (CRC), which maps digital pixel values to relative radiance. The algorithm is fixed at construction time.

Typical usage:

• Create an Hdr object.
• Optionally calculate the response curve using EstimateResponseCurve.
• Generate the HDR image using Process.

Note

All input images must have the same resolution, the same pixel format and be captured from an identical viewpoint of the same scene without any change in camera position or scene content. Any mismatch may lead to invalid HDR reconstruction results.

Limitations:

• All input images must be compatible (same resolution, pixel format, and scene).
• At least two input images must be provided.
• Only the Debevec HDR algorithm is currently supported.

Since

IDSImaging.Peak.ICV 1.3

Constructor & Destructor Documentation

Hdr()

Hdr ( )

inline

Constructs an HDR processing object.

Creates and initializes an HDR object using the default HDR reconstruction algorithm (Debevec).

Since

IDSImaging.Peak.ICV 1.3

Member Function Documentation

Dispose()

void Dispose ( )

inline

Releases all resources.

Since

IDSImaging.Peak.ICV 1.3

EstimateResponseCurve()

void EstimateResponseCurve ( IEnumerable< Image > images )

inline

Estimates the Camera Response Curve (CRC) from a set of input images.

This method calculates the response characteristics of the camera sensor. The CRC defines the relationship between scene radiance and the measured pixel values.

All input images must meet the following conditions:

• Represent the same scene.
• Be compatible in size and pixel format.
• Contain valid metadata for either exposure time or gain, and the values for the chosen parameter must vary across the given images (e.g., DeviceExposureTime or DeviceGain).

Performing this estimation step explicitly can significantly reduce the processing time of subsequent calls to Process, as the curve does not need to be re-calculated.

If this method is not called, the response curve is estimated automatically during the first call to Process.

Supported pixel formats

Mono8 RGB8

See the Pixel and Pixel Format Specifications for a detailed description of the pixel formats.

Parameters

images

Images of the same scene with different exposure time or gain metadata. Must not be empty.

Exceptions

ArgumentNullException	images is null.
IcvNotPossibleException	The class is already disposed.

Since

IDSImaging.Peak.ICV 1.3

Process()

Image Process ( IEnumerable< Image > images )

inline

Generates an HDR image from the specified input images.

Processes the provided images and combines them into a single HDR image.

If a pixel is under- or overexposed across all input images this pixel is clamped to the HDR image's global minimum or maximum values, respectively. All clamped pixels are excluded from the image region.

All input images must meet the following conditions:

• Represent the same scene.
• Be compatible in size and pixel format.
• Contain valid metadata for either exposure time or gain, and the values for the chosen parameter must vary across the given images (e.g., DeviceExposureTime or DeviceGain).

If the camera response curve has not been explicitly estimated using EstimateResponseCurve, an internal estimation step is performed automatically wenn this is first called. This may increase the overall processing time for the first call.

Supported pixel formats

Mono8 RGB8

See the Pixel and Pixel Format Specifications for a detailed description of the pixel formats.

Parameters

images

Images of the same scene with different exposure time or gain metadata. Must not be empty.

Returns

The resulting HDR image with pixel format Mono32f resp. RGB32f.

Exceptions

IcvNullPointerException	The given image enumerable is null or empty.
IcvNotPossibleException	The class is already disposed.

Since

IDSImaging.Peak.ICV 1.3

Property Documentation

Algorithm

HdrAlgorithm Algorithm

get

Returns the HDR algorithm used by this object.

The algorithm is defined at construction time and determines how the input images are combined during HDR reconstruction.

Since

IDSImaging.Peak.ICV 1.3

ResponseCurve

ResponseCurve ResponseCurve

getset

Exceptions

IcvNotPossibleException

No response curve is currently set. Use the setter of this property or EstimateResponseCurve to set a response curve first.

Since

IDSImaging.Peak.ICV 1.4