Approvals were obtained from the Ethical and Review Committee of participating Universities before the commencement of the data collection exercise. This was done to ensure and guarantee that the data collection task would not hurt the health of the volunteers and that the publication of the data collected would not infringe on their privacy in any way. Also, all volunteers (willingly without any form of cohesion or pressure) agreed to participate in the iris data collection task with the awareness that the collected data would be made publicly available for research purposes. The privacy of the volunteers was respected as personal details that could make the data traceable to them were not collected.

A Vista EY2H dual iris camera was employed for the iris image capture. The iris camera is a RoHS compliant device that uses a cutting-edge, high-resolution CMOS sensor to produce ISO/IEC 19794-6-compliant images of both irises simultaneously. The camera uses a multi-wavelength near-infrared band of light (NIR: 700nm - 900nm) illumination for superior iris images in all environments. The capturing process meets international eye safety requirements and also has a live eye anti-Spoof detection feature that can be used to reliably detect when a subject is alive. At a click of the capture button, a large 2560 by 720-pixel iris image was produced from the camera; this image is automatically separated into four images with a dimension of 640 by 480 pixels. These are the left and right iris images with the iris region localized, and another set of left and right iris images without the iris section localized. An overview of the camera is provided in Figures 1a-c:

Images have been reproduced from Vista Imaging ⁸ with the appropriate permissions.

Digital Weighing scale: a digital weighing scale as shown in Fig. 2 was employed to measure the weight (soft biometric data) of volunteers.

Digital Height Measurement Scale: a height measurement scale as shown in Fig. 3 was employed to measure the height of the volunteers.

Three standard approaches are generally employed for iris image capturing. They are self-enrollment; handheld, self-enrollment (fixed on a tripod); and operator-assisted enrolment. For fast and accurate data capture, the operator-assisted enrolment method was used. The capture device was fixed on a tripod and volunteers were only asked to place their forehead horizontally with their eyes gazing at the lens of the camera. When a perfect range of the irises had been set, the operator clicked the capture button on the camera to initiate the capture process. The captured images were automatically saved on the investigator’s personal computer connected to the scanning device. Afterward, soft biometric features such as: volunteer’s height, weight, age, gender, and state of origin were collected with the respective measuring devices. The data collection sheet shown in Figure 4 was used to initially document the data collected

Detailed information about the iris data collected is presented in this section.

The human iris images presented in this data article are publicly available on Mendeley Data. The dataset contains 8192 human iris images obtained from 1028 volunteers who were students and members of staff in two Nigerian Universities. The human iris images were captured using a handheld VistaEY2H dual iris camera. The first category of images was captured when the volunteers wore spectacles while the second category of images was captured when the volunteers wore no spectacles. The third category contains iris images captured from volunteers that used print-patterned contact lenses. Moreover, the capture device automatically took four images for each category. All images were saved in .bmp image format. In addition, soft biometrics such as height, weight, age, gender, and state of origin were also collected.

(a)  First category of images collected

The VistaEY2H dual iris camera used for the automatic capture produced four images per volunteer at each capturing instance. These are the right and left iris images of each volunteer as shown in Figure 5, the right and left iris images of each volunteer with the iris region automatically localized; this is shown in Figure 6, the right iris image of the volunteer as shown in Figure 7 and left iris image of the individual as shown in Figure 8.

(b)  Second category of images collected

The second category of images was collected from volunteers that wore spectacles. The images generated were the right and left iris images of each volunteer (as shown in Figure 9), the right and left iris images of each volunteer with the iris region automatically localized (this is shown in Figure 10), right iris image of the volunteer as shown in Figure 11 and left iris image of the volunteer as shown in Figure 12.

(c)  Third category of images collected

The third category was captured from volunteers that used print-patterned contact lenses. Only four images were captured from volunteers in this category as they were not asked to put on spectacles. However, the use of print-patterned contact lenses was not popular among the population considered, therefore, only eight volunteers used lenses. Examples of these images are provided in Figures 13-16.

(d)  Soft biometric features

Soft biometric features of each volunteer were also recorded. These are the age, gender, height, weight, and State of origin of volunteers. For instance, the soft biometric features for volunteer B are shown in Table 1:

To easily distinguish the images, the capturing device automatically generated a unique identification number for each image. For instance, the corresponding unique identification number for each image captured from volunteers A and B are presented in Table 2:

The supplementary file in Excel format contains the detailed unique identification number for each iris image as well as the biometric features for each volunteer. cell A of the supplementary file is the serial number of the image, cell B contains the last six digits of the unique identification number of a volunteer without spectacles, and cell C contains the last six digits of the unique identification number of the same volunteer with spectacles while cells D to H contain the soft biometric traits of the same volunteer.

A total number of 1028 volunteers participated in the iris image capturing task. The gender of volunteers is provided in Figure 17. The age range of the volunteers are provided in Figure 18.