Application of the Adobe Photoshop Software Package in Leaf Blade Area Measurement of Woody Plants

Abstract

There are a number of applied methods for determining morphometric parameters, including the area of leaf blades of woody plants: millimeter graph paper method, method of direct measurements, punching method, and planimetric method. The analysis and practical application of the methods in the test mode revealed their shortcomings related to inaccuracy of measurements, experiment duration, and equipment inaccessibility. Many researchers have successfully acquired digitized images. However, capturing the parameters of the considered structure from the monitor screen is often impossible due to the low availability of morphometric programs and their high cost. The purpose of the work is to evaluate the effectiveness of existing methods for determining the area of leaf blades on the example of the birch genus (Betula L.) trees and to accumulate the algorithm for determining morphometric parameters of birch leaf blades in the Adobe Photoshop software package. We have developed a method for determining morphometric parameters of leaf blades of woody plants using the Adobe Photoshop software package. The research subject is the leaf blades of birch trees. This method requires: blank A4 sheets; a ruler with an angle of 90°; transparent adhesive tape (scotch tape); and a scanner. We draw a reference square of random (but fixed) dimensions in a random corner of each sheet, step by 10 mm from its borders, on a blank A4 sheet using a ruler with an angle of 90°. The square is placed strictly parallel to the sheet borders. Then, leaf blades of the desired wood species are attached to the sheet with scotch tape. Using the scanner, we convert the workpiece into electronic form and upload the image to Adobe Photoshop. In order to receive morphometric parameters, you can use the following program tools: “ruler”, “magic wand”, “magnetic lasso tool”. At the same time, it is possible to automatically select the borders of the studied object, which helps to avoid subjective errors. The resulting measurements are displayed in pixels and then converted to the required units. The obtained data is verified using the reference square. Verification showed that the method accuracy is more than 99.9 %. The proposed method allows to perform fast and accurate measurements of morphometric parameters of leaf blades, without requiring the purchase of expensive equipment, which makes it available to any researcher who faces with the task of measuring the surface of leaf blades of woody plants. For citation: Babaev R.N. Application of the Adobe Photoshop Software Package in Leaf Blade Area Measurement of Woody Plants. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 5, pp. 185–191. DOI: 10.37482/0536-1036-2021-5-185-191