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我试图LinearDNG在我的 MacOS 应用程序中打开文件。据我调查，这是不可能的CoreImage。

所以，问题：

  1. LinearDNG是否可以使用16 位/8 位 RGBA 数据打开文件CoreImage？
  2. LinearDNG是否可以使用16 位/8 位 RGBA 数据打开文件dcraw？
  3. 您知道将LinearDNG文件作为 16 位/8 位 RGBA 数据打开的其他库吗？

我的 LinearDNG 文件是 16 位的。相关EXIF数据：

File Type                       : DNG
File Type Extension             : dng
MIME Type                       : image/x-adobe-dng

Bits Per Sample                 : 16 16 16
Compression                     : Uncompressed
Photometric Interpretation      : Linear Raw

Format                          : image/jpeg

我读过CIContext可以将图像转换为TIFF/JPEG，但是带有此特定LinearDNG文件的代码不起作用。所有 JPEG 图像都是黑色的，所有 TIFF 图像都是透明的。我想CIImage只是不理解这种编码。

我的测试代码：

[self convertLinearDNGToJPEG:@"super_jpeg.jpeg"];
        
[self convertLinearDNGToTIFF:kCIFormatRGBA8 fileName:@"super_kCIFormatRGBA8.tiff"];
[self convertLinearDNGToTIFF:kCIFormatRGBA16 fileName:@"super_kCIFormatRGBA16.tiff"];
[self convertLinearDNGToTIFF:kCIFormatARGB8 fileName:@"super_kCIFormatARGB8.tiff"];
[self convertLinearDNGToTIFF:kCIFormatRGBAh fileName:@"super_kCIFormatRGBAh.tiff"];

对应的函数（convertLinearDNGToTIFF/ convertLinearDNGToJPEG ）：

- (void)convertLinearDNGToJPEG:(NSString*)fileName
{
    CIImage* inputImage = [self createInputImage];
    
    NSError* superError = nil;
    CIContext* ciContext = [self createCiContext];
    
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    
    NSURL* superURL = [NSURL fileURLWithPath: [documentsDirectory stringByAppendingPathComponent:fileName] ];
    CGColorSpaceRef superColorSpace = CGColorSpaceCreateDeviceRGB();
    [ciContext writeJPEGRepresentationOfImage:inputImage
                                        toURL:superURL
                                   colorSpace:superColorSpace
                                      options:@{} // CIImageRepresentationOption
                                        error:&superError];
}
- (void)convertLinearDNGToTIFF:(CIFormat)format fileName:(NSString*)fileName
{
    CIImage* inputImage = [self createInputImage];
    
    NSError* superError = nil;
    CIContext* ciContext = [self createCiContext];
    
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    
    NSURL* superURL = [NSURL fileURLWithPath: [documentsDirectory stringByAppendingPathComponent:fileName] ];
    CGColorSpaceRef superColorSpace = CGColorSpaceCreateDeviceRGB();
    [ciContext writeTIFFRepresentationOfImage:inputImage
                                        toURL:superURL
                                       format:format
                                   colorSpace:superColorSpace
                                      options:@{} // CIImageRepresentationOption
                                        error:&superError];
}
4

1 回答 1

1

好吧，我试过 LibRaw：https ://github.com/LibRaw/LibRaw 。它能够将我的导出LinearDNG到 TIFF。我可以用CoreImage. 但是白平衡是错误的。我认为这是因为libraw读取元数据错误（文件samples/raw-identify.cpp）。

导出到 TIFF 的代码在文件中samples/simple_dcraw.cpp

/* -*- C++ -*-
 * File: simple_dcraw.cpp
 * Copyright 2008-2020 LibRaw LLC (info@libraw.org)
 * Created: Sat Mar  8, 2008
 *
 * LibRaw simple C++ API:  emulates call to "dcraw  [-D]  [-T] [-v] [-e] [-4]"

LibRaw is free software; you can redistribute it and/or modify
it under the terms of the one of two licenses as you choose:

1. GNU LESSER GENERAL PUBLIC LICENSE version 2.1
   (See file LICENSE.LGPL provided in LibRaw distribution archive for details).

2. COMMON DEVELOPMENT AND DISTRIBUTION LICENSE (CDDL) Version 1.0
   (See file LICENSE.CDDL provided in LibRaw distribution archive for details).


 */
#include <stdio.h>
#include <string.h>
#include <math.h>

#include "libraw/libraw.h"

#ifndef LIBRAW_WIN32_CALLS
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/mman.h>
#endif

#ifdef LIBRAW_WIN32_CALLS
#define snprintf _snprintf
#endif

int my_progress_callback(void *unused_data, enum LibRaw_progress state,
                         int iter, int expected)
{
  if (iter == 0)
    printf("CB: state=%x, expected %d iterations\n", state, expected);
  return 0;
}

char *customCameras[] = {
    (char *)"43704960,4080,5356, 0, 0, 0, 0,0,148,0,0, Dalsa, FTF4052C Full,0",
    (char *)"42837504,4008,5344, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF4052C 3:4",
    (char *)"32128128,4008,4008, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF4052C 1:1",
    (char *)"24096096,4008,3006, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF4052C 4:3",
    (char *)"18068064,4008,2254, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF4052C 16:9",
    (char *)"67686894,5049,6703, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF5066C Full",
    (char *)"66573312,4992,6668, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF5066C 3:4",
    (char *)"49840128,4992,4992, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF5066C 1:1",
    (char *)"37400064,4992,3746, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF5066C 4:3",
    (char *)"28035072,4992,2808, 0, 0, 0, 0,0,148,0,0,Dalsa, FTF5066C 16:9",
    NULL};

int main(int ac, char *av[])
{
  int i, ret, verbose = 0, output_thumbs = 0;

  // don't use fixed size buffers in real apps!
  char outfn[1024], thumbfn[1024];

  LibRaw* RawProcessor = new LibRaw;
  RawProcessor->imgdata.params.custom_camera_strings = customCameras;
  if (ac < 2)
  {
    printf("simple_dcraw - LibRaw %s sample. Emulates dcraw [-D] [-T] [-v] "
           "[-e] [-E]\n"
           " %d cameras supported\n"
           "Usage: %s [-D] [-T] [-v] [-e] raw-files....\n"
           "\t-4 - 16-bit mode\n"
           "\t-L - list supported cameras and exit\n"
           "\t-v - verbose output\n"
           "\t-T - output TIFF files instead of .pgm/ppm\n"
           "\t-e - extract thumbnails (same as dcraw -e in separate run)\n",
           LibRaw::version(), LibRaw::cameraCount(), av[0]);
    delete RawProcessor;
    return 0;
  }

  putenv((char *)"TZ=UTC"); // dcraw compatibility, affects TIFF datestamp field

#define P1 RawProcessor->imgdata.idata
#define S RawProcessor->imgdata.sizes
#define C RawProcessor->imgdata.color
#define T RawProcessor->imgdata.thumbnail
#define P2 RawProcessor->imgdata.other
#define OUT RawProcessor->imgdata.params

  for (i = 1; i < ac; i++)
  {
    if (av[i][0] == '-')
    {
      if (av[i][1] == 'T' && av[i][2] == 0)
        OUT.output_tiff = 1;
      if (av[i][1] == 'v' && av[i][2] == 0)
        verbose++;
      if (av[i][1] == 'e' && av[i][2] == 0)
        output_thumbs++;
      if (av[i][1] == '4' && av[i][2] == 0)
        OUT.output_bps = 16;
      if (av[i][1] == 'C' && av[i][2] == 0)
        RawProcessor->set_progress_handler(my_progress_callback, NULL);
      if (av[i][1] == 'L' && av[i][2] == 0)
      {
        const char **clist = LibRaw::cameraList();
        const char **cc = clist;
        while (*cc)
        {
          printf("%s\n", *cc);
          cc++;
        }
        delete RawProcessor;
        exit(0);
      }
      continue;
    }

    if (verbose)
      printf("Processing file %s\n", av[i]);

    if ((ret = RawProcessor->open_file(av[i])) != LIBRAW_SUCCESS)
    {
      fprintf(stderr, "Cannot open_file %s: %s\n", av[i], libraw_strerror(ret));
      continue; // no recycle b/c open file will recycle itself
    }

    if (!output_thumbs) // No unpack for thumb extraction
      if ((ret = RawProcessor->unpack()) != LIBRAW_SUCCESS)
      {
        fprintf(stderr, "Cannot unpack %s: %s\n", av[i], libraw_strerror(ret));
        continue;
      }

    // thumbnail unpacking and output in the middle of main
    // image processing - for test purposes!
    if (output_thumbs)
    {
      if ((ret = RawProcessor->unpack_thumb()) != LIBRAW_SUCCESS)
      {
        fprintf(stderr, "Cannot unpack_thumb %s: %s\n", av[i],
                libraw_strerror(ret));
        if (LIBRAW_FATAL_ERROR(ret))
          continue; // skip to next file
      }
      else
      {
        snprintf(thumbfn, sizeof(thumbfn), "%s.%s", av[i],
                 T.tformat == LIBRAW_THUMBNAIL_JPEG ? "thumb.jpg"
                                                    : "thumb.ppm");

        if (verbose)
          printf("Writing thumbnail file %s\n", thumbfn);
        if (LIBRAW_SUCCESS != (ret = RawProcessor->dcraw_thumb_writer(thumbfn)))
        {
          fprintf(stderr, "Cannot write %s: %s\n", thumbfn,
                  libraw_strerror(ret));
          if (LIBRAW_FATAL_ERROR(ret))
            continue;
        }
      }
      continue;
    }

    ret = RawProcessor->dcraw_process();

    if (LIBRAW_SUCCESS != ret)
    {
      fprintf(stderr, "Cannot do postpocessing on %s: %s\n", av[i],
              libraw_strerror(ret));
      if (LIBRAW_FATAL_ERROR(ret))
        continue;
    }
    snprintf(outfn, sizeof(outfn), "%s.%s", av[i],
             OUT.output_tiff ? "tiff" : (P1.colors > 1 ? "ppm" : "pgm"));

    if (verbose)
      printf("Writing file %s\n", outfn);

    if (LIBRAW_SUCCESS != (ret = RawProcessor->dcraw_ppm_tiff_writer(outfn)))
      fprintf(stderr, "Cannot write %s: %s\n", outfn, libraw_strerror(ret));

    RawProcessor->recycle(); // just for show this call
  }
  
  delete RawProcessor;
  return 0;
}
于 2020-07-10T07:22:32.743 回答