目的 打印图像在数模/模数转换过程中，主要涉及到RGB、CIELAB和CMYK 3个颜色空间。本文基于DCT域水印算法，在不同颜色空间嵌入水印图像，研究并分析颜色空间对打印图像水印性能的影响。方法 选取暗调、饱和色、风景、亮调、人物、中性灰6类图像分为低中高3个复杂度分别在RGB、LAB、CMYK颜色空间下的各个分量图像中进行透明性、鲁棒性评价。结果 经透明性分析，RGB空间B通道、Lab空间b通道和CMYK空间M通道嵌入水印透明性更好;鲁棒性分析可知，亮调图像在RGB空间抗非几何攻击能力较差，各类型低复杂度图像在LAB空间抗攻击性能差，所有图像在CMYK前三通道的抗攻击性能优于K通道，抗打印攻击能力上暗调图像抗此攻击性能差，所有图像在LAB空间抗打印攻击性能最好，其中L通道最好。结论 本文系统研究了颜色空间对打印图像水印性能的影响。结果显示，颜色空间对不同类型和不同复杂度的图像水印性能具有不同程度的影响。完善了数字水印技术在打印图像应用中的理论体系，同时将为彩色图像数字水印技术的工业化应用和优化提供一定的指导和借鉴。

In digital-to-analog/analog-to-digital conversion, printed images mainly involve three color spaces:RGB, CIELAB and CMYK. The work aims to embed watermarking images in different color spaces based on the DCT-domain watermarking algorithm. Six types of images including dark tone, saturated tone, landscape, bright tone and human figure and neutral grey were selected to evaluate the transparency and robustness in each component image in RGB, LAB and CMYK color spaces with three complexity levels respectively. According to the transparency analysis, the transparency of watermark embedded in Lab space b channel, RGB space B channel and CMYK space M channel was better. According to the robustness analysis, images in bright tone had poor resistance to non-geometric attacks in the RGB space. The anti-attack performance of all images in the first three channels of CMYK was better than that in K channel. The anti-attack performance of all images in dark tone was poor in anti-print attack capability. The anti-print performance of all images in the LAB space was the best, among which that in L channel was the best. In this work, the effect of color spaces on the watermarking performance of printed images is systematically studied. The results show that color spaces have different effects on watermarking performance of image of different types and complexity. It improves the theoretical system of digital watermarking technology in the application of printed images, and will provide some guidance and reference for the industrial application and optimization of color image digital watermarking technology.