摘要 |
<p>A method of calibrating a computer-controlled printing machine to produce printed copies of an original image to a pre-determined standard, comprises: using the printing machine to print a reproduction of a step wedge, having patches with densities concentrated in a central region of the density range, with the machine set to dot gain values corresponding to pre-determined density values on a standard dot gain profile; formulating a revised dot gain profile having the same shape as the standard dot gain profile but with a maximum dot gain which is equal to the maximum measured dot gain and which is located at the density having the maximum measured dot gain; determining revised dot gain values for the predetermined density values from the revised dot gain profile; and setting the dot gain values in the printing machine in accordance with the revised dot gain values.</p> |