To acquire a High Dynamic Range(HDR) image from the Low Dynamic Range(LDR) image acquisition equipment
the HDR image production technology was researched based on different exposure images in the same scene. Then
a CCD irradiance calibration method which doesn't require low noise images as the input was proposed. To avoid the deviation from the global optimum solution by excessive number of parameters
an energy function with fewer parameters consisting of the parameter model of CCD irradiance response curve
a residual penalty function
and a weighting function was proposed. The energy function was optimized by a low fitting error EMoR parameter model
squared residual penalty function suppressing image Gaussian noise
and the weighting function balancing image noise with deadline domain interference. Then the parameters were solved by minimizing energy function with Levenberg Marquardt(LM) algorithm which switched from rapid iteration to accurate iteration. Experimental results indicate that
with different number of model parameters and intensities of image noise
the response curve fitting Root Mean Squared Error(RMSE)\[0.0022
0.0163\]
the accuracy is increased by 39%-90%
the processing time is reduced by 38%-56%
and the obtained HDR-LDR mapping image is more similar with LDR image sequences and all the details of bright and dark regions are visible clearly.
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references
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