I'm currently working on compressing audio files using DCT to remove the frequencies that only contribute marginally to human perception of the sound. To do this, I'd like to do as the attached image describes. Sadly, I'm having trouble plotting the values of the DCT-coefficients as done in figure 6.4 b) and d). 

Any help would be kindly appreciated.

I'm working with Fourier Transform. I'd like to transform a noisy image to the frequency domain, create a grayscale version of the spectrum, mask the dots or lines, threshold it, multiply the binary mask image with the magnitude image and then transform back to the spatial domain. Is this possible using Maple?

Any help would be appreciated.

Currently working on Fourier series. Having trouble plotting the graph of the Fourier series and would love to add and use a package such as the one found here: https://www.maplesoft.com/applications/view.aspx?SID=4857 . I'm having trouble installing and using the package, though. Could anyone be so kind as to assist me in adding and using packages not already found in Maple?