Licensing optionsfor this format begin with FME Professional Edition.
FME provides read and write access to the Esri .hdr header file and the associated raw raster file, along with an Esri world file.
概述
An Esri .hdr file is a header file that stores the georeferencing information of an associated raw raster file. The georeferencing information is read or written to an Esri world file but is also stored in the .hdr file with the following keywords:
Keyword |
价值 |
nrows |
The number of rows in the image. Rows are parallel to the x-axis of the map coordinate system. There is no default. |
ncols |
The number of columns in the image. Columns are parallel to the y-axis of the map coordinate system. There is no default. |
nbands |
The number of spectral bands in the image. The default is 1. |
nbits |
每个频段每像素的比特数。可接受的值是1,4,8,16和32.默认值是每个像素每个像素的八位。对于具有三个带（R，G，B）的真实彩色图像（R，G，B），每个频带中的每个像素的8位存储，Nbits等于八个，nBands等于三个，总共每像素的二十四位。对于具有等于1的Nbits的图像，NBABRS还必须相等。 |
pixeltype |
If this keyword is present and its values is signedint, then the data is assumed to be a signed integer type. Otherwise, the data is assumed to be an unsigned integer type. |
byteOrder. |
The byte order in which image pixel values are stored. The byte order is important for sixteen-bit images, with two bytes per pixel. Acceptable values are I, which is Intel byte order (Silicon Graphics, DEC Alpha, PC) or little-endian, and M, which is Motorola byte order (Sun, HP, etc.) or big-endian. The default byte order is the same as that of the host machine executing the software. |
布局 |
在图像文件中的频带组织。可接受的值是BIL，其是通过线路交错的频带，BIP是由像素交错的带和BSQ，其是频带顺序。默认布局是bil。 |
skipbytes |
The number of bytes of data in the image file to skip in order to reach the start of the image data. This keyword allows you to bypass any existing image header information in the file. The default value is zero bytes. |
ulxmap |
The x-axis map coordinate of the center of the upper-left pixel. If you specify this parameter, set ulymap, too, otherwise a default value is used. |
ulymap |
左上像素中心的Y轴映射坐标。如果指定此参数，则还必须设置ULXMAP，否则使用默认值。 |
xdim |
The x-dimension of a pixel in map units. If this parameter is specified, ydim must also be set, otherwise a default value is used. |
ydim |
The y-dimension of a pixel in map units. If this parameter is specified, xdim must also be set; otherwise a default value is used. |
For example, if you have a 2500 (width) x 4000 (height) external image format image with cell size of 10 and the coordinate of the center of the upper-left pixel of (330000, 6500000), the image will have
ULXMAP = 329995, ULYMAP = 6500005, XDIM = 10, and YDIM = 10
For each raster, there is only a single feature returned, since this feature will contain the entire raster.
请注意，当前版本的ESRI .HDR光栅读卡器/作家不支持bandrowbytes, totalrowbytes, andbandgapbyteskeywords. This format also supports an optional colormap ASCII file that allows for an RGB palette to be stored in a separate .clr file if present.
The raw data file for Esri .hdr datasets can have multiple extensions depending on the interleaving type of the file. The extension becomes one of the following allowable interleaving options: BIP, BSQ, BIL. Thus an Esri dataset with a band order by pixel interleaving would have a .hdr file and a .bip file.
如果存在并与ESRI .HDR数据集一起写入ESRI世界文件。世界文件扩展也匹配数据集的交错类型。
b |
.bpw |
BSQ |
.bqw |
Bil. |
.blw |
读者概述
FME considers a single file to be a dataset.
Writer Overview
ESRI .HDR编写器创建并将数据写入Workbench Navigator中目标参数中指定的单个文件夹。
The Esri .hdr writer distinguishes duplicate output files by appending numbers to the filenames.
FME Raster Features
FME栅格功能代表光栅数据，并使用与矢量数据处理中使用的那些概念不同的概念。下面的主题描述了FME如何处理栅格数据。
Esri .hdr supports rasters with an arbitrary number of bands, provided all bands are the same data type and no band has a palette. Esri .hdr also supports rasters with a single band that has a palette.