This technology is a transform-domain contrast enhancement device that performs a wavelet transform on an original image to divide it into low-frequency and high-frequency sub-bands, applies Contrast Limited Adaptive Histogram Equalization (CLAHE) only to the low-frequency sub-band, and then reconstructs the image using a two-stage synthesizer.
While spatial domain histogram equalization is a standard method for increasing contrast, it often causes artifacts such as unnatural regions or amplified noise due to large peaks in the histogram. Processing solely in the spatial domain without addressing frequency information makes it difficult to enhance contrast while preserving fine details.
By performing equalization and region normalization only in the low-frequency band, which contains brightness distribution, and separately synthesizing edge information from the high-frequency band, this technology expands the dynamic range of brightness without losing detail, resulting in superior image quality compared to existing methods. It can be applied to medical imaging, night-vision or backlight surveillance cameras, and display enhancement engines to render dark or hazy images with clear contrast.
This invention was developed with support from the Small and Medium Business Administration for resolving technical difficulties in large-capacity image analysis for film inspection equipment.
N/A
