An image processing apparatus, which supplies image signals to an image forming apparatus, includes a storage unit that stores a limiting value of a sum of signal levels of output image signals, an input unit that inputs C, M, Y and K signals, a first comparison unit that compares the limiting value and the sum of the signal levels, an under color removal unit that replaces a predetermined level of C, M and Y signals with a K signal in an under color removal process when the sum of the signal levels of the input signals exceeds the limiting value, a second comparison unit that compares the limiting value and the sum after undergoing the under color removal process, and where the sum after the under color removal process exceeds the limiting value, an adjustment unit that reduces the C, M and Y signals after undergoing the under color removal process at an identical rate so as to reduce the sum to less than the limiting value.