3,108 research outputs found
Flash Photography Enhancement via Intrinsic Relighting
We enhance photographs shot in dark environments by combining a picture taken with the available light and one taken with the flash. We preserve the ambiance of the original lighting and insert the sharpness from the flash image. We use the bilateral filter to decompose the images into detail and large scale. We reconstruct the image using the large scale of the available lighting and the detail of the flash. We detect and correct flash shadows. This combines the advantages of available illumination and flash photography.Singapore-MIT Alliance (SMA
Color Image Enhancement Method Based on Weighted Image Guided Filtering
A novel color image enhancement method is proposed based on Retinex to
enhance color images under non-uniform illumination or poor visibility
conditions. Different from the conventional Retinex algorithms, the Weighted
Guided Image Filter is used as a surround function instead of the Gaussian
filter to estimate the background illumination, which can overcome the
drawbacks of local blur and halo artifact that may appear by Gaussian filter.
To avoid color distortion, the image is converted to the HSI color model, and
only the intensity channel is enhanced. Then a linear color restoration
algorithm is adopted to convert the enhanced intensity image back to the RGB
color model, which ensures the hue is constant and undistorted. Experimental
results show that the proposed method is effective to enhance both color and
gray images with low exposure and non-uniform illumination, resulting in better
visual quality than traditional method. At the same time, the objective
evaluation indicators are also superior to the conventional methods. In
addition, the efficiency of the proposed method is also improved thanks to the
linear color restoration algorithm.Comment: 15 page
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