C ++ LibTiff-从内存读取和保存文件 [英] C++ LibTiff - Read and Save file from and to Memory

问题描述

在LibTiff中有一种方法可以从内存中读取文件并将其保存到内存中吗?

Is there a way in LibTiff how I can read a file from Memory and save it to Memory?

在使用其他库打开图像之前，我不想先将图像保存到光盘上.

I don't want to save the image to the disc first, before opening it with an other library...

非常感谢！

推荐答案

我知道这是一个老问题，但是对于像我这样需要这些信息的人，我将发布一个更简单，最新的答案. libtiff的最新版本.在libtiff的最新版本(4.0.2)中，甚至我相信过去的几个版本(请检查您的特定版本号)中，都有一个名为tiffio.hxx的包含文件.它具有两个用于读取/写入内存中流的外部函数:

I know this is an old question, but I am going to post an easier, more up-to-date answer for those like myself who need this information for more recent versions of libtiff. In the newest version of libtiff (4.0.2), and even the past few versions I believe (check for your specific version number), there is an include file called tiffio.hxx. It has two extern functions for reading/writing to streams in memory:

extern TIFF* TIFFStreamOpen(const char*, std::ostream *);
extern TIFF* TIFFStreamOpen(const char*, std::istream *);

您可以仅包含此文件并读取或写入内存.

You can just include this file and read or write to memory.

写作示例:

#include <tiffio.h>
#include <tiffio.hxx>
#include <sstream>    

std::ostringstream output_TIFF_stream;

//Note: because this is an in memory TIFF, just use whatever you want for the name - we 
//aren't using it to read from a file
TIFF* mem_TIFF = TIFFStreamOpen("MemTIFF", &output_TIFF_stream);

//perform normal operations on mem_TIFF here like setting fields
//...

//Write image data to the TIFF 
//..

TIFFClose(mem_TIFF);   

//Now output_TIFF_stream has all of my image data. I can do whatever I need to with it.

阅读非常相似:

#include <tiffio.h>
#include <tiffio.hxx>
#include <sstream>

std::istringstream input_TIFF_stream;
//Populate input_TIFF_stream with TIFF image data
//...

TIFF* mem_TIFF = TIFFStreamOpen("MemTIFF", &input_TIFF_stream);

//perform normal operations on mem_TIFF here reading fields
//...

TIFFClose(mem_TIFF);

这些是非常简单的示例，但是您可以看到，通过使用TIFFStreamOpen，您不必重写这些函数并将它们传递给TIFFClientOpen.​​

These are very simple examples, but you can see that by using TIFFStreamOpen you don't have to override those functions and pass them to TIFFClientOpen.

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