1.  Field of the Invention
The present invention relates to an information processing apparatus and method for realizing optimization, or the like, of a calibration operation in on-demand printing, for example. 
2.  Description of the Related Art
In recent years, on-demand printing has been increasingly popular at production sites, resulting from an improvement of printing technology due to digitalization in image forming apparatuses, color management technology for controlling image forming apparatuses, order acceptance via the Internet, automation of pagination, and the like.  Characteristics of on-demand printing lie in that a very small lot can be handled, the delivery time is short, and there is a wide variety of product lineup and options in order to meet demand of each customer. 
To prevent degradation of tone caused by long-time printing or aged deterioration of an image forming apparatus, it is necessary to regularly calibrate the printer, whereas there is a demand for optimizing a calibration operation at production sites of on-demand printing, which has the aforementioned characteristics.  This is because, in on-demand printing, various types of items in a very small lot are produced in a short delivery time, and therefore the production sites cannot take much time to execute calibration.  If too much time and effort are taken to execute calibration, it will affect the production plan based on the premise of a short delivery time. 
There is a technique for optimizing execution of calibration by measuring the density of a patch between sheets if the number of printed sheets after implementing calibration reaches a threshold value, and giving an instruction to implement calibration if the measurement result is smaller than a predetermined threshold value (see Japanese Patent Laid-Open No.  2006-243480. 
Japanese Patent Laid-Open No.  2006-243480 discloses that the density of a patch between sheets is measured if the number of printed sheets reaches a prescribed number, and an instruction to implement tone correction in accordance with the measurement result is given.  However, for example, in the case where the same tone needs to be applied to parts, such as a cover and a wraparound band, of an item, such as a photobook, a photo album, or a manual, that is constituted by a plurality of parts including a cover, main text, a wraparound band, and the like, calibration needs to be performed for each part regardless of the number of sheets to be printed, and it is difficult, with the technique recited in Japanese Patent Laid-Open No.  2006-243480, to reduce the frequency of calibration. 
For example, a photobook is one of the items with many parts that is produced in on-demand printing.  A photobook is constituted by four parts, namely a wraparound band, main text, a cover, and a jacket.  Different types of paper are used for the respective parts.  At production sites of photobooks, printing is performed for each part in order to save time and effort to switch paper. 
In the case of printing the same image on the cover and the wraparound band of a photobook, the tones of printed colors on the cover and the wraparound band are expected to be the same.  However, if printing is performed for each part at a production site in order to save time and effort to switch paper as mentioned above, that is to say, if initially the cover is solely printed and the wraparound band is printed thereafter, the tones of printed colors on the cover, which is printed first, and the wraparound band, which is printed next, are possibly different.  Accordingly, to apply the same tone to the image printed on the cover and the image printed on the wraparound band, a target used in calibration that has been performed before the execution of printing on the cover prior to starting printing on the wraparound band needs to be selected from a panel to implement calibration. 
Moreover, the time and effort for calibration cannot be reduced even in the case where the same item is reordered.  In the case of a reorder, there is a demand, at production sites, for printing copies for the reorder with the same tone as the tone used for the previous order.  For example, if a customer purchases one copy of a photobook on a trial basis and then orders the same photobook once again since he/she likes the trial copy he/she ordered, the copy for the reorder needs to be produced with the same tone as the tone used in the trial copy.  In this case, if it is attempted to apply the same tone as the tone for the previous order to printing for the reorder, production needs to be stopped for each part for the reorder before printing is performed, in order to select the previous target from the panel to perform calibration.  Accordingly, calibration for each part is still necessary, and it is difficult to reduce the frequency of calibration.  Since calibration in the middle of printing decreases the efficiency in production of an item, the production efficiency is lower as the frequency thereof is higher. 
The present invention has been made in view of the above-described conventional example, and provides an information processing apparatus and method with which an increase in the frequency of calibration is prevented.  In particular, the present invention provides an information processing apparatus and method with which an increase in the frequency of calibration is prevented in the case where the same tone needs to be applied to colors printed on different types of paper.