Abstract: A method of determining health of a plant which method includes displaying, on a screen of an electronic display of a mobile computing device, a digital leaf colour chart with colours ranging from yellow green to dark green; displaying on the screen next to the digital leaf colour chart a white area on which a leaf of the plant is to be placed; receiving input to the mobile computing device from a user about which colour of the digital leaf colour chart that best matches the leaf placed on the white area; and the mobile computing device determining the plant health based on the received input.

Abstract: A method of estimating chlorophyll content of a leaf including providing a device wherein the device includes a mobile computing device with a digital camera; and a peripheral removably attached to the mobile computing device, the peripheral including a light source aligned with the digital camera, wherein the peripheral provides for a space between the light source and the digital camera; capturing by the digital camera a first image of the light source turned on without the leaf interposed between the digital camera and the light source; retrieving exposure data of the first image; capturing by the digital camera a second image with the leaf interposed between the digital camera and the turned on light source; retrieving exposure data of the second image; and using a processor, estimating the chlorophyll content of the leaf based on the retrieved exposure data of the first and second images.

Abstract: A method of determining health of a plant which method includes displaying, on a screen of an electronic display of a mobile computing device, a digital leaf colour chart with colours ranging from yellow green to dark green; displaying on the screen next to the digital leaf colour chart a white area on which a leaf of the plant is to be placed; receiving input to the mobile computing device from a user about which colour of the digital leaf colour chart that best matches the leaf placed on the white area; and the mobile computing device determining the plant health based on the received input.

Abstract: A method of estimating chlorophyll content of a leaf including providing a device wherein the device includes a mobile computing device with a digital camera; and a peripheral removably attached to the mobile computing device, the peripheral including a light source aligned with the digital camera, wherein the peripheral provides for a space between the light source and the digital camera; capturing by the digital camera a first image of the light source turned on without the leaf interposed between the digital camera and the light source; retrieving exposure data of the first image; capturing by the digital camera a second image with the leaf interposed between the digital camera and the turned on light source; retrieving exposure data of the second image; and using a processor, estimating the chlorophyll content of the leaf based on the retrieved exposure data of the first and second images.