The parts of an ICT kit (left) and reference colour card (right) (a). An ICT kit showing a positive result (b) with a band at both control (C) and test (T) lines. An ICT kit showing a negative result (c) with a band only at the C line. The intensity value of the colour image is specified by the red, green, and blue parameters as separate integers from 0 to 255 with the 8-bit representation of a pixel in the image. The intensity values were plotted for C and T lines of the positive (d) and negative (e) ICT kits. The intensity values (d and e) were related to colour band intensity of C and T lines in the strips. S indicates sample hole.