存储嵌入式地图应用程序的图像
我有不同分辨率的光栅化地图，其中包含 15K/60K/240K 图片，每个尺寸为 256x256，并且我有可以显示地图的 .NET Compact Framework 应用程序。 但是将300k文件复制到SD卡需要很多时间，大约需要35-60小时（我只复制了15K，花了大约2到2.5小时），而且我担心它会破坏FAT16文件系统（硬件不支持） FAT32，所以我无法将 fat16 切换到 fat32），否则复制所有内容后运行速度会非常慢。
所有图片都这样存储： /mapdata/res{resolution}/x{x_coord}/y{y_coord}.png
任何嵌入式数据库都可以帮助我吗？或者我应该将图像打包成 zip 像 /storage/res1/x12.zip 并存档所有 y*.png 吗？或者我应该用所有这些图片创建 ISO 映像，然后将 ISO 逐字节复制到 SD？
I have rasterized map in different resolutions, which consists of 15K/60K/240K pictures each sized 256x256, and i have .NET Compact Framework application which can display the map.
But it takes a lot of time to copy 300k files to SD card, approximately 35-60 hours (i copyied just 15K and it took ~ 2 to 2.5 hours), and i'm afraid it will ruin FAT16 filesystem (hardware does not support FAT32, so i can't switch fat16 to fat32) or after copying everything will work very slow.
All pictures are stored like this: /mapdata/res{resolution}/x{x_coord}/y{y_coord}.png
Can any embeddable DB help me? Or should i pack images into zip like /storage/res1/x12.zip with all y*.png archived? Or i just should create ISO-image with all these pictures and just copy iso to SD byte-to-byte?
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FAT16 仅限于 65,535 个簇，每个文件至少需要一个簇，这将排除仅使用平面文件的可能性。
我假设您的地图图块是只读的，所以我会采取一种为您控制的图块创建自定义文件格式的方法（可能还具有需要更多努力来分解的额外好处，应该它落入错误的手中）。
也许是这样的：
查找给定图块的偏移量，并在报告流结束时覆盖流以执行“正确的事情”，这将是相对轻量级的 - 如果您要编码，您甚至可以对“无图块”图片使用相同的偏移量无法完全融入正方形的区域（例如英国）
FAT16 is limited to 65,535 clusters, and a minimum of a single cluster is required per file, which will rule out just using flat files.
I'm assuming your map tiles are to be read-only, so I would take a route of creating a custom file format for your tiles that you control (may also have the added benefit of requiring a bit more effort to take apart, should it fall into the wrong sort of hands).
Maybe something along the lines of:
It would be relatively lightweight to look up the offsets for a given tile, and override a Stream to do "the right thing" when reporting end of the Stream - you could even use the same offset for "no tile" pictures should you be encoding an area that doesn't fit neatly into a square (like, say, Great Britain)