有时候用 spm12的Display选项打开nifti之后发现nifti数据文件的数据类型是不一样的,比如int16和float32,会心生疑惑,两种数据类型对数据分析有影响吗? 事实上,nifti文件的大小就但等于dimensions乘以数据类型的长度,比如下图中数据大小应该是64 64 33*16=2162688位,换算成Kb应该是2162688/1024/8=264Kb,那我们再来看一下这个nifti文件的大小呢?如图所示,确实是265Kb。 至于nifti的int16与32float有什么区别,我觉得下面的这个回答还算满意(原文链接: https://afni.nimh.nih.gov/afni/community/board/read.php?1,137005,137007 ): giuseppe pagnoni Wrote: I have noticed that when copying NIFTI data (from a Philips scanner) with 3dcopy, an automatic conversion from INT16 to FLOAT32 seems to be taking place [...] But why is that happening? Is there a way to keep the original format? If the data are originally INT16, it seems to me that you waste a lot of disk space and computing time by doubling the size of the data right away. In my understanding int16 was used in AFNI in the old days, when disk space was expensive. Nowadays disk space is quite cheap, so it's not too much of an issue. When using int16, data is stored together with a min val...
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