Get the number of objects drawn in the process colors.
int pdfGetNumProcessColorObjects(PDFHandle pdf, int idx)
This function returns the number of objects drawn using each of the four process colors (cyan, magenta, yellow, and black), on the pages specified in the last call to pdfAnalyzePages. Objects are generally counted multiple times: for example, an object drawn with C=1, M=0.5, Y=0, K=0 would be counted in both cyan and magenta (i.e., it marks both the C and M plates).

The idx argument specifies which process color, and should be one of the following constants:

int i, nC, nM, nY, nK; /* analyze page 1 */ pdfAnalyzePages(pdf, 1, 1); nC = pdfGetNumProcessColorObjects(pdf, pdfProcessC); nM = pdfGetNumProcessColorObjects(pdf, pdfProcessM); nY = pdfGetNumProcessColorObjects(pdf, pdfProcessY); nK = pdfGetNumProcessColorObjects(pdf, pdfProcessK);