An important challenge of Digital Cultural Heritage is to contribute to the recovery of artworks with their original shape and appearance. Many altarpieces, which are very relevant Christian art elements, have been damaged and/or, partly or fully, lost. Therefore, the only way to recover them is to carry out their digital reconstruction. Although the procedure that we present here is valid for any altarpiece with similar characteristics, and even for other akin elements, our test bench is the altarpieces damaged, destroyed, or disappeared during the Spanish Civil War (1936-1939) in Catalonia where most suffered these effects. The first step of our work has been the classification of these artworks into different categories on the basis of their degree of destruction and of the available visual information related to each one.

This paper proposes, for the first time to our knowledge, a workflow for the virtual reconstruction, through photogrammetry, digital modeling, and digital color restoration; of whole altarpieces partially preserved with very little visual information. Our case study is the Rosary’s altarpiece of Sant Pere Màrtir de Manresa church. Currently, this altarpiece is partially preserved in fragments in the Museu Comarcal de Manresa (Spain). But, it can not be reassembled physically owing to the lack of space (actually the church does not exist anymore) and the cost of such an operation. Thus, there is no other solution than the digital one to contemplate and study the altarpiece as a whole. The reconstruction that we provide allows art historians and the general public to virtually see the altarpiece complete and assembled as it was until 1936. The results obtained also allow us to see in detail the reliefs and ornaments of the altarpiece with their digitally restored color.

数字文化遗产的一个重要挑战是帮助恢复艺术品的原始形状和外观。许多与基督教艺术元素密切相关的祭坛画已被损坏和/或部分或全部丢失。因此，恢复它们的唯一方法就是进行数字重建。虽然我们在这里介绍的程序对于任何具有类似特征的祭坛画，甚至其他类似元素都有效，但我们的测试台是西班牙内战（1936-1939）期间在加泰罗尼亚遭受损坏、毁坏或消失的祭坛画，那里是受灾最严重的地区。这些影响。我们工作的第一步是根据这些艺术品的破坏程度和与每件艺术品相关的可用视觉信息将它们分为不同的类别。

据我们所知，本文首次提出了通过摄影测量、数字建模和数字色彩恢复进行虚拟重建的工作流程；整个祭坛画部分保留，视觉信息很少。我们的案例研究是 Sant Pere Màrtir de Manresa 教堂的念珠祭坛画。目前，这幅祭坛画的部分碎片保存在曼雷萨科马卡尔博物馆（西班牙）。但是，由于缺乏空间（实际上教堂已经不存在）和这种操作的成本，它无法在物理上重新组装。因此，除了数字解决方案之外，没有其他解决方案可以从整体上思考和研究祭坛画。我们提供的重建工作使艺术历史学家和公众能够虚拟地看到祭坛画直到 1936 年的完整和组装状态。获得的结果还使我们能够详细看到祭坛画的浮雕和装饰品及其数字修复的颜色。