An image display device for generating output image data by correcting an input image on the basis of Retinex theory, the image display device comprising: separation means configured to separate an illumination light component and reflectance component from the input image using a filter; corrected illumination light component calculation means configured to calculate a corrected illumination light component (L') and generation means configured to generate the output image data on the basis of the corrected illumination light component (L') and reflectance, the image display device being characterised in that: the corrected illumination light component calculation means calculates the corrected illumination light component (L') by summing up the separated illumination light component and a low-gradation component-enhanced illumination light component, the low-gradation component-enhanced illumination light component obtained by adjusting a low-gradation component of the illumination light component according to the relationship L1 = (log(LAmp ∗ L +1))/(log(LAmp+1)), and LAmp is an enhancement degree adjustment parameter, and wherein the summing up is made according to L' = LGain ∗ L1+(1-LGain) ∗ L, and LGain is a parameter for determining the combination ratio at which the low-gradation component-enhanced illumination component and the separated illumination component are combined. separation means configured to separate an illumination light component and reflectance component from the input image using a filter; corrected illumination light component calculation means configured to calculate a corrected illumination light component (L') and generation means configured to generate the output image data on the basis of the corrected illumination light component (L') and reflectance, the image display device being characterised in that: the corrected illumination light component calculation means calculates the corrected illumination light component (L') by summing up the separated illumination light component and a low-gradation component-enhanced illumination light component, the low-gradation component-enhanced illumination light component obtained by adjusting a low-gradation component of the illumination light component according to the relationship L1 = (log(LAmp ∗ L +1))/(log(LAmp+1)), and LAmp is an enhancement degree adjustment parameter, and wherein the summing up is made according to L' = LGain ∗ L1+(1-LGain) ∗ L, and LGain is a parameter for determining the combination ratio at which the low-gradation component-enhanced illumination component and the separated illumination component are combined. the corrected illumination light component calculation means calculates the corrected illumination light component (L') by summing up the separated illumination light component and a low-gradation component-enhanced illumination light component, the low-gradation component-enhanced illumination light component obtained by adjusting a low-gradation component of the illumination light component according to the relationship L1 = (log(LAmp ∗ L +1))/(log(LAmp+1)), and LAmp is an enhancement degree adjustment parameter, and wherein the summing up is made according to L' = LGain ∗ L1+(1-LGain) ∗ L, and LGain is a parameter for determining the combination ratio at which the low-gradation component-enhanced illumination component and the separated illumination component are combined.