It is necessary to examine the dying behavior of dye combination from a practical point of view to achieve a proper colour uniformity to have an acceptable match of the standard sample to obtain satisfactory repeatability and to minimize chemical and energy consumption. During the previous year there have been vast technological changes in all industries, especially textile industry. As the dyeing processes are complicated, the tendency to reduce the time of the dyeing process is increased and consequently it is vital to use optimization and controlling the process with computers. Thus a shorter dyeing procedure, higher productivity and less chemical consumption should be achieved in any dyeing process. Also, achieving colour uniformity by adding chemicals increasing the dyeing time or raising the temperature is not perfect and it is favorable to use compatible dyes for which the rate of dyeing is similar and hence the dyes are exhausted equally in all dyeing cycles. Many visual and instrumental techniques have been introduced to determine the compatibility of dyes all of which are on the basis of spectral reflectance or absorbance data. In the present research the compatibility of dyes is determined by using scanner joined with a computer program, which reproduce the spectra of the diptest samples. To do so, firstly the sample dyed with cationic and acid dyes are scanned by a characterized scanner. Then the image of each sample is processed to obtain the XYZ of it and next using a PCA method the spectral reflectance of the sample is reproduced. Afterward the compatibility factor is determined using percentage cumulative variance method introduced by Khalili and Amirshahi. Then the compatibility factor obtained by the scanner is compared with one calculated using the Khalili and Amirshahi method by using a spectrophotometer. The results show that it is conceivable to predict the compatibility of dyes by the proposed scanner method properly if characterization accuracy of the scanner is suitable.