Method and device for quantification of plant chlorophyll content
A system for measuring chlorophyll concentration in a leaf sample includes a leaf-holding illuminator device with a main body containing a power source, a plurality of switchable light sources emitting light at different spectra (e.g., red and white light from a broadband light source), and a cap detachably secured to the main body using one or more fastening means. The leaf sample is interposed between the main body and the cap and held in place during imaging. The system includes a mobile electronic device having a camera configured to capture an image of the leaf illuminated by the plurality of switchable light sources, the mobile electronic device having wireless connectivity to a network and an application contained therein configured to transfer the images to a remote sever or computer via the network for data processing. A final chlorophyll index value is calculated based on the transferred images.
1. A system for measuring chlorophyll concentration in a leaf sample comprising:
a leaf-holding illuminator device comprising a main body containing a power source, a plurality of switchable light sources emitting light at different spectra, a diffuser interposed within an optical path formed between the plurality of switchable light sources and the leaf, and a cap having an aperture therein that is detachably secured to the main body, wherein the leaf sample is interposed between the main body and the cap; and
a mobile electronic device having a camera configured to capture images of the leaf illuminated by the plurality of switchable light sources, the mobile electronic device having wireless connectivity to a network and an application stored therein configured to transfer the images to a remote computer via the network.
2. The system of claim 1 , wherein the mobile electronic device comprises a wearable imaging device.
3. The system of claim 2 , wherein the mobile electronic device comprises a glasses-based imaging device.
4. The system of claim 1 , wherein the mobile electronic device comprises one of a mobile phone, tablet, and webcam.
5. The system of claim 1 , wherein the mobile electronic device captures images of transmitted light through the leaf.
6. The system of claim 1 , wherein the mobile electronic device captures images of reflected light from the leaf.
7. The system of claim 1 , wherein the plurality of switchable light sources comprises a red light source and a broadband light source.
8. The system of claim 1 , wherein the cap comprises a base connected to an extension.
9. The system of claim 1 , wherein at least one of the cap and main body has fastening means for detachably securing the cap to the main body.
10. A method of measuring chlorophyll concentration in a leaf sample comprising;
loading the leaf sample into a leaf-holding illuminator device;
illuminating the leaf sample with a leaf-holding illuminator device at a first illumination spectrum with a first illumination source and a second illumination spectrum with a second illumination source;
capturing images of the illuminated leaf sample with a camera of a mobile electronic device while being illuminated at the first illumination spectrum and the second illumination spectrum;
the mobile electronic device transferring the captured images at the first illumination spectrum and the second illumination spectrum to a remote server;
the remote server extracting a region of interest (ROI) from each of the transferred images and computing an average intensity value for the ROI obtained by the first illumination source and an average intensity value for the ROI obtained by the second illumination source;
the remote server generating a chlorophyll index value for the first illumination source based on a comparison of the average intensity value for ROI obtained by the first illumination source with a calibration curve;
the remote server generating a chlorophyll index value for the second illumination source based on a comparison of the average intensity value for ROI obtained by the second illumination source with a calibration curve;
the remote server calculating a final chlorophyll index value based on a function applied to the chlorophyll index value for the first illumination source and the chlorophyll index value for the second illumination source; and
transferring the final chlorophyll index value from the remote server to the mobile electronic device.
11. The method of claim 10 , wherein the mobile electronic device comprises a glasses-based imaging device.
12. The method of claim 10 , wherein the remote server calculates the final chlorophyll index value based on an average of the chlorophyll index value for the first illumination source and the chlorophyll index value for the second illumination source.
13. The method of claim 10 , wherein the captured images of the illuminated leaf sample comprises transmitted light.
14. The method of claim 10 , wherein the captured images of the illuminated leaf sample comprises reflected light.
15. The method of claim 10 , wherein the first illumination source emits red light and the second illumination source emits a broadband spectrum of light.
16. The method of claim 10 , wherein the chlorophyll index value comprises a chlorophyll content index (CCI).
17. The method of claim 10 , wherein a dedicated application executed on the mobile electronic device transmits the captured images at the first illumination spectrum and the second illumination spectrum to the remote server and receives the final chlorophyll index value.
18. The method of claim 10 , wherein the leaf-holding illuminator device is held by a person with a first hand and a second hand of the person holds the mobile electronic device during the image capturing operation.
19. The method of claim 10 , wherein the leaf-holding illuminator device and the mobile electronic device are mounted on a support base.
20. A method of measuring chlorophyll concentration in a leaf sample comprising;
loading the leaf sample into a leaf-holding illuminator device;
illuminating the leaf sample with a leaf-holding illuminator device at a first illumination spectrum with a first illumination source and a second illumination spectrum with a second illumination source;
capturing images of the illuminated leaf sample with a camera of a mobile electronic device while being illuminated at the first illumination spectrum and the second illumination spectrum;
the mobile electronic device transferring the captured images at the first illumination spectrum and the second illumination spectrum to a remote server;
the remote server extracting a region of interest (ROI) from each of the transferred images and computing an average intensity value for the ROI obtained by the first illumination source and an average intensity value for the ROI obtained by the second illumination source;
the remote server generating a chlorophyll index value for the first illumination source based on a comparison of the average intensity value for ROI obtained by the first illumination source with a calibration curve;
the remote server generating a chlorophyll index value for the second illumination source based on a comparison of the average intensity value for ROI obtained by the second illumination source with a calibration curve;
the remote server transferring the chlorophyll index value for the first illumination source and the chlorophyll index value for the second illumination source to the mobile electronic device;
the mobile electronic device calculating a final chlorophyll index value based on the chlorophyll index value for the first illumination source and the chlorophyll index value for the second illumination source.