YCbCr pulsed illumination scheme in a light deficient environment
The disclosure extends to methods, systems, and computer program products for producing an image in light deficient environments with luminance and chrominance emitted from a controlled light source.
1. A digital imaging method for use with an endoscope in ambient light deficient environments comprising:
actuating an emitter to emit a pulse of a wavelength of electromagnetic radiation to cause illumination within the light deficient environment;
wherein said pulse is within a wavelength range that comprises a portion of electromagnetic spectrum;
pulsing said emitter at a predetermined interval;
sensing reflected electromagnetic radiation from said pulse with a pixel array;
wherein said pixel array is actuated at a sensing interval that corresponds to the pulse interval of said emitter; and
synchronizing the emitter and the imaging sensor so as to produce a plurality of image frames wherein the plurality of image frames comprises a luminance frame comprising luminance image data only and a chrominance frame comprising chrominance data only that are combined to form a color image.
2. The method of claim 1 , wherein the emitter comprises a plurality of sources that each emits a pulse of a portion of electromagnetic spectrum.
3. The method of claim 2 , further comprising actuating the plurality of sources simultaneously.
4. The method of claim 3 , further comprising pulsing the plurality of sources at a predetermined interval.
5. The method of claim 1 , further comprising adjusting the pulse to provide luminance information during the luminance frame, by matching to color space conversion coefficients.
6. The method of claim 1 , further comprising adjusting the pulse to provide chrominance information during the chrominance frame to match to color space conversion coefficients.
7. The method of claim 6 , wherein the chrominance information is blue.
8. The method of claim 6 , wherein the chrominance information is red.
9. The method of claim 1 , further comprising pulsing the emitter to produce a pulsing pattern of luminance, chrominance blue, luminance, chrominance red.
10. The method of claim 1 , further comprising pulsing the emitter to produce a pulsing pattern of luminance, chrominance blue combined with chrominance red, luminance, chrominance blue combined with chrominance red.
11. The method of claim 1 , wherein the controller is configured to use chrominance frames more than once to reconstruct resultant frames.
12. The method of claim 1 , further comprising compensation with a luminance coefficient to chrominance frames by and image signal processor and wherein the luminance coefficient is an integer that is a multiple of (½)n.
13. The method of claim 1 , wherein the image sensor comprises uniform pixels configured to be read individually.
14. The method of claim 13 , reading data from the image sensor at a plurality of frame durations wherein the plurality of frame durations produce long exposures and short exposures.
15. The method of claim 14 , wherein the image sensor is configured to produce a sequence of frames comprising:
a luminance frame of long exposure pixel data and short exposure pixel data,
a red chrominance frame of long exposure pixel data and short exposure pixel data, and
a blue chrominance frame of long exposure pixel data and short exposure pixel data.
16. The method of claim 15 , further comprising sensing the luminance wavelength so it is represented in the pattern twice as often as the red and blue chrominance wavelengths.
17. The method of claim 1 , wherein a pulse of electromagnetic radiation emitted by the emitter is of a wavelength that is not visible to humans.
18. The method of claim 2 , wherein the plurality of electromagnetic wavelengths comprises wavelengths that are visible to humans and that are not visible to humans.
19. The method of claim 1 , actuating the emitter so as to emit the plurality of electromagnetic wavelengths at differing magnitudes.
20. The method of claim 19 , wherein the differing magnitudes correspond to the imaging sensor's sensitivity to differing wavelengths.
21. The method of claim 1 , further comprising blanking said pixel array at a predetermined blanking interval that corresponds to said sensing interval.