真实感绘制对于细节的要求越来越高,应用程序通常采用多幅或大幅分辨率很高的纹理图像,有限的内存空间就成了一个制约的瓶颈.针对纹理图像的特点和可编程图形硬件的特殊要求,该文提出了一种新的面向绘制的编码算法——增量式纹理编码算法及相应的解压绘制算法,有效地解决了纹理存储容量和真实感之间的矛盾,并利用可编程图形硬件实现了实时解压绘制,该算法在图像压缩编码过程中,动态添加码表内容,只有当已有码表内容不能表示当前图像区域时,才增加码表内容.这种方法不仅能够对于自相似性较强的纹理图像取得很高的压缩比,而且由于码表的动态更新特性,可以对图像序列进行流式编码.在绘制纹理时,该算法充分利用了现有可编程图像硬件的特性,实现了实时解压绘制.文中分别对于静态图像和动态图像序列进行了实验,结果显示,此方法能灵活有效地对各类纹理图像进行编码.
In photorealistic rendering, multiple high-resolution texture images are needed to add details to the scene, which makes the limited texture memory exhausted soon. This paper proposes a novel encoding algorithm for texture image-incremental texture encoding algorithm, for which the compressed textures are decompressed and rendered in real time by programmable graphics hardware. This method gradually fills in the codebook by dynamically adding in the elements when the current codebook can not encode the region of the image being processed. In this way, the method can not only produces high compression ratio for texture images with self-similarity, but also encode the image sequences in a stream-like manner due to the property of dynamically updating the codebook. Experimental results show that the method is effective and efficient in encoding and rendering still/animated textures.