BugwoodIDS:Image quality

This is a guide to the data entry protocols used in the Bugwood Image Database. Each protocol has a list of instructions (in bold) with rationale or notes after each step. Experienced users can skip the notes and follow the steps of the protocol. Questions about the Bugwoood Image Database should be directed to Joe LaForest or any of the Bugwood Image Database Administrators. The Administrator Guide and the User Guide are available and may answer many questions.

Introduction

Making sure that the images in the Bugwood Image Database are reviewed for quality is one thing that sets it apart from other collections of images. The objective is to provide users with the best images to illustrate living things, management practices and all subjects related to Forestry, Integrated Pest Management, Agriculture, Invasive Species, Weed Science, Entomology, Plant Pathology, and a wide range of other disciplines.

Image quality

Graphic representation of depth of field. Middle flower (white section) is in focus. Other flowers are not.

Many factors affect the quality of the image. This is an overview of the various factors that play into the overall quality of an image.

Focus

The main subject of the image should be in focus. This can also be affected by the depth of field. Imagine a series of planes that are parallel to the sensor of the camera. One plane begins the area that is in-focus and one is at the end of the in-focus area. The total area in focus is the depth of field. This can be used effectively to highlight identifying features while obscuring other irrelevant or distracting details.

Uniqueness

Many digital cameras can capture a burst of images. Since these images are taken in a short period of time, they are often very similar. Rather than have several images that are nearly identical with minor differences in angle and zoom, we seek to have a set of distinct images to illustrate the subject. That being said, having two very similar images with a different orientation (portrait vs landscape) would be enough to consider them unique images since the orientation of the image may be key when finding an image to meet a particular use.

Composition

The image should have the subject as the main feature of the image. Having other objects in the foreground or centered in the image that distract the person looking at the image from the main subject can reduce the quality of an image.

Color

The color in the image should accurately represent what the object looked like in real life. This can be difficult with scanned slides but a good approximation can be reached through digital editing. Digital images taken with modern cameras often produce accurate representations bu by be deceptive if light quality is not adequate.

Brightness

The image should be bright enough to highlight the necessary features but not so bright that parts of the image are over-exposed or washed out.