Leaf-IT

Leaf-IT is a new, easy-to-use, and free of charge application, designed for scientific purposes. It is specially designed to measure leaf area under challenging field conditions, includes easy-to-use features for area calculation and data output and can be used for ecological research and teaching.

Leaf-IT is licensed under creative commons, license: CC BY-NC-SA 4.0.

Due to its intuitive graphical user interface and high portability Leaf-IT is useful for a wide range of applications in ecological research and teaching.

Leaf-IT does not require connection to the internet or other databases. No inconvenient and error-prone image calibration is needed, as Leaf-IT provides two types of area referencing: either a ruler or a reference object with known area.

Images of leaves or other objects are taken by the internal camera. When the camera is activated, a level appears. Provided that the photographed object is in level, optimized set up for highest accuracy can thus be created.

Area is calculated by detecting the edge of the leaf. This approach is highly robust against unwanted shadows and impurities which may interfere with area calculation and makes Leaf-IT fundamentally different to other area-analyzing software.

Leaf-IT can also be used to measure other areas providing high contrast between background and object.

To calculate the area two methods can be chosen for setting a reference object.

The first method (Set size of leaf manually) allows the user to place an object of a known length (e.g. a ruler or any other defined object) next to the leaf. By manually drawing a rectangle around the reference object, it is spared from image processing for not interfering in edge detection of the leaf. After edge detection the user can adjust a digital ruler to the reference object and enter the length.

The second method (Use reference object) allows the user to place an object with a known area (e.g. a coin or a printed rectangle) next to the leaf. Both reference and leaf are processed separately (again by placing a digital rectangle around the reference object). After the image is processed, the user enters the area of the reference object

For best results, the leaf should be placed on a background with a high contrast to the leaf. A white background works best for darker leaves. For lighter objects such as flower petals, a black background might be more suitable.

Area measurements obtained from standardized objects show that Leaf-IT measures area with high accuracy and precision.

Leaf-IT offers intuitive tools for data management, export, and image acquisition.

A “Project”-menu allows the user to create own projects, which can be for instance a measurement series of a certain plant individual or species, a field site, or a sampling day. Each project can later be exported as a single csv-file. All image calculations within one project are saved in the same csv-file where also species names and image IDs can be edited and deleted.