Patent Number: 
Section: claims

1. An x-ray source for performing energy discrimination within an imaging system comprising:a plurality of cathode-emitting devices emitting a plurality of electrons; anda single rotating anode having a plurality of targets oriented whereupon said plurality of electrons impinge to generate a plurality of x-ray beams; anda plurality of filters simultaneously filtering said plurality of x-ray beams to generate a post-filter x-ray beam having an x-ray distribution with simultaneously a plurality of x-ray quantity versus energy peaks defined as a plurality of peaks in the number of x-rays at multiple energy levels. 2. An x-ray source as in claim 1 wherein said a plurality of cathode-emitting device comprises:a first cathode-emitting device emitting a first plurality of electrons; anda second cathode-emitting device emitting a second plurality of electrons. 3. An x-ray source as in claim 2 wherein said first cathode-emitting device emits said first plurality of electrons at a first kVp and said second cathode-emitting device emits said second plurality of electrons at a second kVp. 4. An x-ray source as in claim 1 wherein said plurality of filters comprises a stationary filter. 5. An x-ray source as in claim 1 wherein said plurality of filters comprises a rotating filter. 6. An x-ray source as in claim 1 wherein said plurality of filters comprises:a first filter filtering a first x-ray beam; anda second filter filtering a second x-ray bear. 7. An x-ray source as in claim 1 comprising:a first filter having a first energy pass range; anda second filter having a second energy pass range. 8. An x-ray source as in claim 1 wherein said plurality of targets are on different sides of said single rotating anode. 9. An x-ray source as in claim 1 wherein said plurality of targets are on different surfaces of said single rotating anode. 10. An imaging system comprising:an x-ray source comprising;a plurality of cathode-emitting devices emitting a plurality of electrons; andat least one anode having at least one target oriented relative to said plurality of cathode-emitting devices whereupon said plurality of electrons impinge to generate a plurality of x-ray beams; anda plurality of filters simultaneously filtering said plurality of x-ray beams to generate a post-filter x-ray beam having simultaneously a plurality of x-ray quantity versus energy peaks defined as a plurality of peaks in the quantity of x-rays at a plurality energy levels; andan energy differentiating detector receiving said post-filter x-ray beam and generating an x-ray signal having material energy density differentiating information. 11. An imaging system as in claim 10 comprising:a filter rotating device coupled to said plurality of filters; anda controller electrically coupled to said filter rotating device and rotating said plurality of filters. 12. An imaging system as in claim 11 wherein said controller transitions between each filter in said plurality of filters for each view within a plurality of views. 13. An imaging system as in claim 10 further comprising an x-ray detector measuring a plurality of x-ray quantity energy levels of said x-ray beam. 14. An imaging system as in claim 13 wherein said x-ray detector measures said plurality of x-ray quantity energy levels corresponding to each of said plurality of x-ray quantity peaks. 15. An imaging system as in claim 13 wherein said x-ray detector measures said plurality of x-ray quantity energy levels in at least one energy bin.