Function LoadEXRFromMemory

Synopsis

#include <tinyexr.h>

int LoadEXRFromMemory(float **out_rgba, int *width, int *height, const unsigned char *memory, size_t size, const char **err)

Description

NOT YET IMPLEMENTED: Saves single-frame OpenEXR deep image. Returns negative value and may set error string in err when there's an error extern int SaveDeepEXR(const DeepImage *in_image, const char *filename, const char **err); NOT YET IMPLEMENTED: Loads multi-part OpenEXR deep image. Application must free memory of variables in DeepImage(image, offset_table) extern int LoadMultiPartDeepEXR(DeepImage **out_image, int num_parts, const char *filename, const char **err); For emscripten. Loads single-frame OpenEXR image from memory. Assume EXR image contains RGB(A) channels. Returns negative value and may set error string in err when there's an error When there was an error message, Application must free err with FreeEXRErrorMessage()

Mentioned in

  • Getting Started / TODO

Source

Lines 11470-11657 in tinyexr.h. Line 454 in tinyexr.h.

int LoadEXRFromMemory(float **out_rgba, int *width, int *height,
                      const unsigned char *memory, size_t size,
                      const char **err) {
  if (out_rgba == NULL || memory == NULL) {
    tinyexr::SetErrorMessage("Invalid argument for LoadEXRFromMemory", err);
    return TINYEXR_ERROR_INVALID_ARGUMENT;
  }

  EXRVersion exr_version;
  EXRImage exr_image;
  EXRHeader exr_header;

  InitEXRHeader(&exr_header);

  int ret = ParseEXRVersionFromMemory(&exr_version, memory, size);
  if (ret != TINYEXR_SUCCESS) {
    tinyexr::SetErrorMessage("Failed to parse EXR version", err);
    return ret;
  }

  ret = ParseEXRHeaderFromMemory(&exr_header, &exr_version, memory, size, err);
  if (ret != TINYEXR_SUCCESS) {
    return ret;
  }

  // Read HALF channel as FLOAT.
  for (int i = 0; i < exr_header.num_channels; i++) {
    if (exr_header.pixel_types[i] == TINYEXR_PIXELTYPE_HALF) {
      exr_header.requested_pixel_types[i] = TINYEXR_PIXELTYPE_FLOAT;
    }
  }

  InitEXRImage(&exr_image);
  ret = LoadEXRImageFromMemory(&exr_image, &exr_header, memory, size, err);
  if (ret != TINYEXR_SUCCESS) {
    return ret;
  }

  // RGBA
  int idxR = -1;
  int idxG = -1;
  int idxB = -1;
  int idxA = -1;
  for (int c = 0; c < exr_header.num_channels; c++) {
    if (strcmp(exr_header.channels[c].name, "R") == 0) {
      idxR = c;
    } else if (strcmp(exr_header.channels[c].name, "G") == 0) {
      idxG = c;
    } else if (strcmp(exr_header.channels[c].name, "B") == 0) {
      idxB = c;
    } else if (strcmp(exr_header.channels[c].name, "A") == 0) {
      idxA = c;
    }
  }

  // TODO(syoyo): Refactor removing same code as used in LoadEXR().
  if (exr_header.num_channels == 1) {
    // Grayscale channel only.

    (*out_rgba) = reinterpret_cast<float *>(
        malloc(4 * sizeof(float) * static_cast<size_t>(exr_image.width) *
               static_cast<size_t>(exr_image.height)));

    if (exr_header.tiled) {
      for (int it = 0; it < exr_image.num_tiles; it++) {
        for (int j = 0; j < exr_header.tile_size_y; j++) {
          for (int i = 0; i < exr_header.tile_size_x; i++) {
            const int ii =
                exr_image.tiles[it].offset_x * exr_header.tile_size_x + i;
            const int jj =
                exr_image.tiles[it].offset_y * exr_header.tile_size_y + j;
            const int idx = ii + jj * exr_image.width;

            // out of region check.
            if (ii >= exr_image.width) {
              continue;
            }
            if (jj >= exr_image.height) {
              continue;
            }
            const int srcIdx = i + j * exr_header.tile_size_x;
            unsigned char **src = exr_image.tiles[it].images;
            (*out_rgba)[4 * idx + 0] =
                reinterpret_cast<float **>(src)[0][srcIdx];
            (*out_rgba)[4 * idx + 1] =
                reinterpret_cast<float **>(src)[0][srcIdx];
            (*out_rgba)[4 * idx + 2] =
                reinterpret_cast<float **>(src)[0][srcIdx];
            (*out_rgba)[4 * idx + 3] =
                reinterpret_cast<float **>(src)[0][srcIdx];
          }
        }
      }
    } else {
      for (int i = 0; i < exr_image.width * exr_image.height; i++) {
        const float val = reinterpret_cast<float **>(exr_image.images)[0][i];
        (*out_rgba)[4 * i + 0] = val;
        (*out_rgba)[4 * i + 1] = val;
        (*out_rgba)[4 * i + 2] = val;
        (*out_rgba)[4 * i + 3] = val;
      }
    }

  } else {
    // TODO(syoyo): Support non RGBA image.

    if (idxR == -1) {
      tinyexr::SetErrorMessage("R channel not found", err);

      // @todo { free exr_image }
      return TINYEXR_ERROR_INVALID_DATA;
    }

    if (idxG == -1) {
      tinyexr::SetErrorMessage("G channel not found", err);
      // @todo { free exr_image }
      return TINYEXR_ERROR_INVALID_DATA;
    }

    if (idxB == -1) {
      tinyexr::SetErrorMessage("B channel not found", err);
      // @todo { free exr_image }
      return TINYEXR_ERROR_INVALID_DATA;
    }

    (*out_rgba) = reinterpret_cast<float *>(
        malloc(4 * sizeof(float) * static_cast<size_t>(exr_image.width) *
               static_cast<size_t>(exr_image.height)));

    if (exr_header.tiled) {
      for (int it = 0; it < exr_image.num_tiles; it++) {
        for (int j = 0; j < exr_header.tile_size_y; j++)
          for (int i = 0; i < exr_header.tile_size_x; i++) {
            const int ii =
                exr_image.tiles[it].offset_x * exr_header.tile_size_x + i;
            const int jj =
                exr_image.tiles[it].offset_y * exr_header.tile_size_y + j;
            const int idx = ii + jj * exr_image.width;

            // out of region check.
            if (ii >= exr_image.width) {
              continue;
            }
            if (jj >= exr_image.height) {
              continue;
            }
            const int srcIdx = i + j * exr_header.tile_size_x;
            unsigned char **src = exr_image.tiles[it].images;
            (*out_rgba)[4 * idx + 0] =
                reinterpret_cast<float **>(src)[idxR][srcIdx];
            (*out_rgba)[4 * idx + 1] =
                reinterpret_cast<float **>(src)[idxG][srcIdx];
            (*out_rgba)[4 * idx + 2] =
                reinterpret_cast<float **>(src)[idxB][srcIdx];
            if (idxA != -1) {
              (*out_rgba)[4 * idx + 3] =
                  reinterpret_cast<float **>(src)[idxA][srcIdx];
            } else {
              (*out_rgba)[4 * idx + 3] = 1.0;
            }
          }
      }
    } else {
      for (int i = 0; i < exr_image.width * exr_image.height; i++) {
        (*out_rgba)[4 * i + 0] =
            reinterpret_cast<float **>(exr_image.images)[idxR][i];
        (*out_rgba)[4 * i + 1] =
            reinterpret_cast<float **>(exr_image.images)[idxG][i];
        (*out_rgba)[4 * i + 2] =
            reinterpret_cast<float **>(exr_image.images)[idxB][i];
        if (idxA != -1) {
          (*out_rgba)[4 * i + 3] =
              reinterpret_cast<float **>(exr_image.images)[idxA][i];
        } else {
          (*out_rgba)[4 * i + 3] = 1.0;
        }
      }
    }
  }

  (*width) = exr_image.width;
  (*height) = exr_image.height;

  FreeEXRHeader(&exr_header);
  FreeEXRImage(&exr_image);

  return TINYEXR_SUCCESS;
}





Add Discussion as Guest

Log in