This picture was taken in one fine night of January in Thailand. As some other dark night shots, this picture has chunks of blue noise and motion blur. Details in the background are missing.

Figure 1. The original picture                                                                                                             Figure 2. The histogram of the original picture

I use High Boost to enhance the picture. The method includes two steps: smoothing to reduce noises; sharpening to extract details.

First, to do gray scale (Figure 3). Then, smoothing, I use Gaussian filter. Figure 4 shows the hisgtogram after implementing Gaussian filter. We can see, the zigzag along the curve has been smoothed a little bit.

After, a matrix of is use to multiply with the resulting image.

Figure 3. The histogram after implementing

Gaussian filter.

Figure 3. The image after gray scale and blur.

Figure 4. The histogram of the image after implementing Gasussian filter.

Figure 4. The final image.

Figure 5. The histogram of the final image.

From figure 5, we can tell that the image is lightened, more details from the dark background is visiable now.

Figure 6. The final image after gray scale.