Atmospheric correction of LANDSAT 7 images in MATLAB

I have used band 5 of LANDSAT images as an example for converting the DN values to radiance. Further, the radiance image is converted to reflectance. The sections are defined as follows;

Step 1: DN to radiance (L) using Gain and Bias method
Step 2: DN to radiance (Lsrc) using Spectral radiance scaling method
Step 3: Radiance (L) to Reflectance (rho)

Just change the image apply the code. Good Luck!