*2.1.3 Dataset details*

The control subjects and Diabetes Mellitus (DM) patients were considered in this study. A total of 35 control subjects and 35 DM patients were recruited from and Hycare for Wounds, Chennai. Both control and DM groups comprise male and female participants, aged between 30 and 65 years. The DM group thermal image collection has been granted by Hycare for Wounds – Institutional Review Board. The participants were informed about the study beforehand and written informed consent forms were obtained from the participants of the study. Sample color and thermal images of the control group and DM group are acquired by the highly sensitive FLIR E60 IR thermal imaging system and are shown in **Figures 3** and **4** (a, b) respectively.

This study is carried out both on acquired and publicly available plantar thermogram database [17–21] for the early detection of diabetic foot. The plantar

*Detection of Diabetic Foot Using Statistical Features DOI: http://dx.doi.org/10.5772/intechopen.106457*

#### **Figure 2.**

*Schematic arrangement for acquisition of thermal image.*

**Figure 3.**

*Control group samples images. (a) Color image of the foot. (b) Thermal image of the foot.*

#### **Figure 4.**

*DM group samples images. (a) Color image of the foot. (b) Thermal image of the foot.*

thermogram database was obtained in a controlled environment 20 1°C using FLIR E60 and FLIR E6 IR thermal imaging system from 122 subjects diagnosed with diabetes (DM group) and 45 healthy subjects (control group). During the thermogram

#### **Figure 5.** *(a) Database thermal image of the foot – Control group. (b) Database thermal image of the foot – DM group.*

acquisition, the position of the camera is fixed by an adjustable vertical tripod to avoid any undesirable movement. The tripod is placed one meter away from the feet. The participants were asked to remove their shoes and socks and clean their feet with a damp towel. After that, the subjects were invited to maintain a supine position for 15 minutes (**Figure 5**).

For each plantar thermogram, the left and right foot were extracted and was taken as a separate thermogram, obtaining a database of 334 individual thermograms. The subjects were recruited from the General Hospital of the North, the General Hospital of the South, the BIOCARE clinic, and the National Institute of Astrophysics, Optics and Electronics (INAOE) over 3 years (from 2012 to 2014). The sample thermal image from the control group and DM group of the database is depicted in **Figure 4**(a) and (b), respectively. The total number of images used in the study is tabulated in **Table 1**, where the left foot and right foot is denoted by LF and RF respectively.

Since the database images are having only the foot region, the segmentation is performed only for the acquired plantar thermal images. The left and right foot regions are segmented from each color image using the region growing algorithm [22]. The red, green, and blue planes are extracted from thermal images and multiplied with the corresponding segmented foot region to get the ROI as a thermal image. The foot position of the left and right foot regions is corrected. **Figure 6**(a) and (b) show the segmented plantar foot regions of the control group and DM group, respectively. The raw temperature profiles of the acquired thermal images are exported as a.csv file from FLIR Tools® thermal analysis and reporting software. The binary image of the segmented foot regions is multiplied with the raw temperature profile of the corresponding foot regions to obtain the temperature distribution for the foot regions.


**Table 1.**

*Number of images in the dataset.*

*Detection of Diabetic Foot Using Statistical Features DOI: http://dx.doi.org/10.5772/intechopen.106457*

**Figure 6.** *(a) Segmented LF and RF regions of the control group. (b) Segmented left and right foot regions of the DM group.*
