wavelength filtering (photos)
If the image is given in the conventional format of sampled pixel values of an sensor matrix, then no it's not possible to apply any software means of EM wavelength/frequency processing on those pixel data. The reason is clear: the sensor pixels are not capturing time variation of electromagnetic wave, they only capture the static (or average) intensity at a point and collectively the intensity distribution along the sensor surface points. Wavelength (and frequency) sensing at a point requires a time domain capture, such as performed by the RF radio antenna or a microphone (sensing the acoustic pressure wave), which therefore enables subsequent frequency/wavelength processing possible.

Therefore practically there remains only a hardware lens filter possbility which is indeed a trusted parctice in the field of photography.

Look for image filters from optics part producers, they can supply any type of filter you want (they are a litle pricey however)