HDR pro に統合...でHDRIを作成した時のカラースペースについて

はい、ファイル情報のRawデータで確認しました。

元データの1枚目（Photoshop CS6 の「HDR に統合」サンプル）

         <crs:CameraProfile>ACR 2.4</crs:CameraProfile>

         <crs:HasSettings>True</crs:HasSettings>

         <crs:HasCrop>False</crs:HasCrop>

         <crs:AlreadyApplied>True</crs:AlreadyApplied>

         <aux:SerialNumber>0860311867</aux:SerialNumber>

         <aux:Lens>18.0-55.0 mm</aux:Lens>

         <xmp:ModifyDate>2005-02-21T16:45:54-08:00</xmp:ModifyDate>

         <xmp:CreateDate>2005-02-06T04:10:46</xmp:CreateDate>

         <xmp:MetadataDate>2005-02-21T16:45:54-08:00</xmp:MetadataDate>

         <photoshop:DateCreated>2005-02-06T04:10:46-08:00</photoshop:DateCreated>

         <photoshop:ColorMode>3</photoshop:ColorMode>

         <photoshop:ICCProfile>Adobe RGB (1998)</photoshop:ICCProfile>

         <xmpMM:DocumentID>CB0DB8B4F9205222285B41769926B991</xmpMM:DocumentID>

         <xmpMM:InstanceID>CB0DB8B4F9205222285B41769926B991</xmpMM:InstanceID>

HDR に統合後

         <crs:CameraProfile>ACR 2.4</crs:CameraProfile>

         <crs:HasSettings>True</crs:HasSettings>

         <crs:HasCrop>False</crs:HasCrop>

         <crs:AlreadyApplied>True</crs:AlreadyApplied>

         <aux:SerialNumber>0860311867</aux:SerialNumber>

         <aux:Lens>18.0-55.0 mm</aux:Lens>

         <xmp:ModifyDate>2005-02-21T16:46:16-08:00</xmp:ModifyDate>

         <xmp:CreateDate>2005-02-06T04:11:50</xmp:CreateDate>

         <xmp:MetadataDate>2005-02-21T16:46:16-08:00</xmp:MetadataDate>

         <photoshop:DateCreated>2005-02-06T04:11:50-08:00</photoshop:DateCreated>

         <photoshop:ColorMode>3</photoshop:ColorMode>

         <photoshop:ICCProfile>Adobe RGB (1998) (線形 RGB プロファイル)</photoshop:ICCProfile>

         <xmpMM:DocumentID>38B61A913C25E2A266227C44B1C15CAC</xmpMM:DocumentID>

         <xmpMM:InstanceID>38B61A913C25E2A266227C44B1C15CAC</xmpMM:InstanceID>

sRGBに変換後の元データの1枚目

         <crs:CameraProfile>ACR 2.4</crs:CameraProfile>

         <crs:HasSettings>True</crs:HasSettings>

         <crs:HasCrop>False</crs:HasCrop>

         <crs:AlreadyApplied>True</crs:AlreadyApplied>

         <aux:SerialNumber>0860311867</aux:SerialNumber>

         <aux:Lens>18.0-55.0 mm</aux:Lens>

         <xmp:ModifyDate>2017-02-04T18:27:48+09:00</xmp:ModifyDate>

         <xmp:CreateDate>2005-02-06T04:10:46</xmp:CreateDate>

         <xmp:MetadataDate>2017-02-04T18:27:48+09:00</xmp:MetadataDate>

         <xmp:CreatorTool>Adobe Photoshop CC 2017 (Macintosh)</xmp:CreatorTool>

         <photoshop:DateCreated>2005-02-06T04:10:46-08:00</photoshop:DateCreated>

         <photoshop:ColorMode>3</photoshop:ColorMode>

         <photoshop:ICCProfile>sRGB IEC61966-2.1</photoshop:ICCProfile>

         <xmpMM:DocumentID>adobe:docid:photoshop:9dd0fc8a-2b4a-117a-841a-e40fa78e6df2</xmpMM:DocumentID>

         <xmpMM:InstanceID>xmp.iid:8f5582cf-496d-40b2-a3c7-3af670da2562</xmpMM:InstanceID>

         <xmpMM:OriginalDocumentID>CB0DB8B4F9205222285B41769926B991</xmpMM:OriginalDocumentID>

sRGBに変換後、HDR に統合

         <crs:CameraProfile>ACR 2.4</crs:CameraProfile>

         <crs:HasSettings>True</crs:HasSettings>

         <crs:HasCrop>False</crs:HasCrop>

         <crs:AlreadyApplied>True</crs:AlreadyApplied>

         <aux:SerialNumber>0860311867</aux:SerialNumber>

         <aux:Lens>18.0-55.0 mm</aux:Lens>

         <xmp:ModifyDate>2017-02-04T18:26:55+09:00</xmp:ModifyDate>

         <xmp:CreateDate>2005-02-06T04:11:50</xmp:CreateDate>

         <xmp:MetadataDate>2017-02-04T18:26:55+09:00</xmp:MetadataDate>

         <xmp:CreatorTool>Adobe Photoshop CC 2017 (Macintosh)</xmp:CreatorTool>

         <photoshop:DateCreated>2005-02-06T04:11:50-08:00</photoshop:DateCreated>

         <photoshop:ColorMode>3</photoshop:ColorMode>

         <photoshop:ICCProfile>sRGB IEC61966-2.1 (線形 RGB プロファイル)</photoshop:ICCProfile>

         <xmpMM:DocumentID>adobe:docid:photoshop:737a0318-2b4a-117a-841a-e40fa78e6df2</xmpMM:DocumentID>

         <xmpMM:InstanceID>xmp.iid:544a88bd-9167-4be2-94c1-2d031c868235</xmpMM:InstanceID>

         <xmpMM:OriginalDocumentID>38B61A913C25E2A266227C44B1C15CAC</xmpMM:OriginalDocumentID>

元データのプロファイルに依存するようでもありますが、sRGBとAdobe RGBの混合ではAdobe RGBになるようです。

（線形 RGB プロファイルとは、多分ガンマ1.0の事なんでしょうか？）