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261 lines
7.6 KiB
ReStructuredText
261 lines
7.6 KiB
ReStructuredText
HDR imaging
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==========
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.. highlight:: cpp
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This section describes high dynamic range imaging algorithms, namely tonemapping, exposure alignment, camera calibration with multiple exposures and exposure fusion.
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Tonemap
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-------------
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.. ocv:class:: Tonemap : public Algorithm
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The base class for tonemapping algorithms - tools, that are used to map HDR image to 8-bit range.
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Tonemap::process
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-----------------------
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Tonemaps image
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.. ocv:function:: void Tonemap::process(InputArray src, OutputArray dst)
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:param src: source image - 32-bit 3-channel Mat
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:param dst: destination image - 32-bit 3-channel Mat with values in [0, 1] range
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TonemapLinear
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--------
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.. ocv:class:: TonemapLinear : public Tonemap
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Simple linear mapper with gamma correction.
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createTonemapLinear
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------------------
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Creates TonemapLinear object
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.. ocv:function:: Ptr<TonemapLinear> createTonemapLinear(float gamma = 1.0f);
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:param gamma: gamma value for gamma correction
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TonemapDrago
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--------
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.. ocv:class:: TonemapDrago : public Tonemap
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"Adaptive Logarithmic Mapping For Displaying HighContrast Scenes", Drago et al.
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createTonemapDrago
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------------------
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Creates TonemapDrago object
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.. ocv:function:: Ptr<TonemapDrago> createTonemapDrago(float gamma = 1.0f, float bias = 0.85f);
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:param gamma: gamma value for gamma correction
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:param bias: value for bias function in [0, 1] range
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TonemapDurand
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--------
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.. ocv:class:: TonemapDurand : public Tonemap
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"Fast Bilateral Filtering for the Display of High-Dynamic-Range Images", Durand, Dorsey, 2002
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This implementation uses regular bilateral filter from opencv.
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createTonemapDurand
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------------------
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Creates TonemapDurand object
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.. ocv:function:: Ptr<TonemapDurand> createTonemapDurand(float gamma = 1.0f, float contrast = 4.0f, float sigma_space = 2.0f, float sigma_color = 2.0f);
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:param gamma: gamma value for gamma correction
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:param contrast: resulting contrast on logarithmic scale
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:param sigma_space: filter sigma in the color space
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:param sigma_color: filter sigma in the coordinate space
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TonemapReinhardDevlin
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--------
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.. ocv:class:: TonemapReinhardDevlin : public Tonemap
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"Dynamic Range Reduction Inspired by Photoreceptor Physiology", Reinhard, Devlin, 2005
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createTonemapReinhardDevlin
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------------------
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Creates TonemapReinhardDevlin object
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.. ocv:function:: Ptr<TonemapReinhardDevlin> createTonemapReinhardDevlin(float gamma = 1.0f, float intensity = 0.0f, float light_adapt = 1.0f, float color_adapt = 0.0f)
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:param gamma: gamma value for gamma correction
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:param intensity: result intensity. Range in [-8, 8] range
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:param light_adapt: light adaptation in [0, 1] range. If 1 adaptation is based on pixel value, if 0 it's global
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:param color_adapt: chromatic adaptation in [0, 1] range. If 1 channels are treated independently, if 0 adaptation level is the same for each channel
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ExposureAlign
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-------------
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.. ocv:class:: ExposureAlign : public Algorithm
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The base class for algorithms that align images of the same scene with different exposures
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ExposureAlign::process
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-----------------------
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Aligns images
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.. ocv:function:: void ExposureAlign::process(InputArrayOfArrays src, OutputArrayOfArrays dst, const std::vector<float>& times, InputArray response)
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:param src: vector of input images
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:param dst: vector of aligned images
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:param times: vector of exposure time values for each image
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:param response: matrix with camera response, one column per channel
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AlignMTB
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--------
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.. ocv:class:: AlignMTB : public ExposureAlign
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"Fast, Robust Image Registration for Compositing High Dynamic Range Photographs from Handheld Exposures", Ward, 2003
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This algorithm does not use exposure values and camera response, new image regions are filled with zeros.
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AlignMTB::process
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-----------------------
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Short version of process, that doesn't take extra arguments.
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.. ocv:function:: void AlignMTB::process(InputArrayOfArrays src, OutputArrayOfArrays dst)
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:param src: vector of input images
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:param dst: vector of aligned images
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AlignMTB::calculateShift
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-----------------------
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Calculates shift between two images.
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.. ocv:function:: void AlignMTB::calculateShift(InputArray img0, InputArray img1, Point& shift)
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:param img0: first image
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:param img1: second image
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:param shift: how to shift the second image to correspond it with the first
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AlignMTB::shiftMat
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-----------------------
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Gelper function, that shift Mat filling new regions with zeros.
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.. ocv:function:: void AlignMTB::shiftMat(InputArray src, OutputArray dst, const Point shift)
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:param src: input image
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:param dst: result image
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:param shift: shift value
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createAlignMTB
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------------------
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Creates AlignMTB object
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.. ocv:function:: Ptr<AlignMTB> createAlignMTB(int max_bits = 6, int exclude_range = 4)
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:param max_bits: logarithm to the base 2 of maximal shift in each dimension
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:param exclude_range: range for exclusion bitmap
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ExposureCalibrate
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-------------
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.. ocv:class:: ExposureCalibrate : public Algorithm
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The base class for camera response calibration algorithms.
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ExposureCalibrate::process
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-----------------------
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Recovers camera response.
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.. ocv:function:: void ExposureCalibrate::process(InputArrayOfArrays src, OutputArray dst, std::vector<float>& times)
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:param src: vector of input images
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:param dst: matrix with calculated camera response, one column per channel
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:param times: vector of exposure time values for each image
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CalibrateDebevec
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--------
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.. ocv:class:: CalibrateDebevec : public ExposureCalibrate
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"Recovering High Dynamic Range Radiance Maps from Photographs", Debevec, Malik, 1997
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createCalibrateDebevec
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------------------
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Creates CalibrateDebevec object
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.. ocv:function:: Ptr<CalibrateDebevec> createCalibrateDebevec(int samples = 50, float lambda = 10.0f)
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:param samples: number of pixel locations to use
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:param lambda: smoothness term weight
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ExposureMerge
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-------------
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.. ocv:class:: ExposureMerge : public Algorithm
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The base class algorithms that can merge exposure sequence to a single image.
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ExposureMerge::process
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-----------------------
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Merges images.
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.. ocv:function:: void process(InputArrayOfArrays src, OutputArray dst, const std::vector<float>& times, InputArray response)
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:param src: vector of input images
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:param dst: result image
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:param times: vector of exposure time values for each image
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:param response: matrix with camera response, one column per channel
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MergeDebevec
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--------
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.. ocv:class:: MergeDebevec : public ExposureMerge
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"Recovering High Dynamic Range Radiance Maps from Photographs", Debevec, Malik, 1997
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createMergeDebevec
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------------------
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Creates MergeDebevec object
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.. ocv:function:: Ptr<MergeDebevec> createMergeDebevec();
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MergeMertens
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--------
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.. ocv:class:: MergeMertens : public ExposureMerge
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"Exposure Fusion", Mertens et al., 2007
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The resulting image doesn't require tonemapping and can be converted to 8-bit image by multiplying by 255.
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MergeMertens::process
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-----------------------
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Short version of process, that doesn't take extra arguments.
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.. ocv:function:: void MergeMertens::process(InputArrayOfArrays src, OutputArray dst)
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:param src: vector of input images
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:param dst: result image
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createMergeMertens
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------------------
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Creates MergeMertens object
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.. ocv:function:: Ptr<MergeMertens> createMergeMertens(float contrast_weight = 1.0f, float saturation_weight = 1.0f, float exposure_weight = 0.0f)
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:param contrast_weight: contrast factor weight
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:param saturation_weight: saturation factor weight
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:param exposure_weight: well-exposedness factor weight |