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63-508: JFIF is mutually incompatible with the newer Exchangeable image file format (Exif). JFIF defines a number of details that are left unspecified by the JPEG Part 1 standard ( ISO / IEC 10918-1, ITU-T Recommendation T.81.) JPEG allows multiple components (such as Y, Cb, and Cr ) to have different resolutions, but it does not define how those differing sample arrays (which render bitmaps) should be aligned. This pixel-producing information

126-458: A FlashPix file. These FlashPix extensions allow meta-information to be preserved when converting between FPXR JPEG images and FlashPix images. FPXR information may be found in images from some models of digital cameras by Kodak and Hewlett-Packard . Below is an example of the FPXR information found in a JPEG image from a Kodak EasyShare V570 digital camera: The Exif specification describes

189-407: A FlashPix file. These FlashPix extensions allow meta-information to be preserved when converting between FPXR JPEG images and FlashPix images. FPXR information may be found in images from some models of digital cameras by Kodak and Hewlett-Packard . Below is an example of the FPXR information found in a JPEG image from a Kodak EasyShare V570 digital camera: The Exif specification describes

252-843: A Global Positioning System sub-IFD using the TIFF Private Tag 0x8825, holding location information, and an "Interoperability IFD" specified within the Exif sub-IFD, using the Exif tag 0xA005. Formats specified in Exif standard are defined as folder structures that are based on Exif-JPEG and recording formats for memory. When these formats are used as Exif/DCF files together with the DCF specification (for better interoperability among devices of different types), their scope shall cover devices, recording media, and application software that handle them. The Exif format has standard tags for location information. As of 2014 , many cameras and mobile phones have

315-676: A Global Positioning System sub-IFD using the TIFF Private Tag 0x8825, holding location information, and an "Interoperability IFD" specified within the Exif sub-IFD, using the Exif tag 0xA005. Formats specified in Exif standard are defined as folder structures that are based on Exif-JPEG and recording formats for memory. When these formats are used as Exif/DCF files together with the DCF specification (for better interoperability among devices of different types), their scope shall cover devices, recording media, and application software that handle them. The Exif format has standard tags for location information. As of 2014 , many cameras and mobile phones have

378-502: A JFIF file will have the following structure: In the mandatory JFIF APP0 marker segment the parameters of the image are specified. Optionally an uncompressed thumbnail can be embedded. Immediately following the JFIF APP0 marker segment may be a JFIF extension APP0 marker segment. This segment may only be present for JFIF versions 1.02 and above. It allows to embed a thumbnail image in 3 different formats. The thumbnail data depends on

441-463: A YCbCr color space, they are typically not decodable by Web browsers and other Internet software. Development of the JFIF document was led by Eric Hamilton of C-Cube Microsystems , and agreement on the first version was established in late 1991 at a meeting held at C-Cube involving about 40 representatives of various computer, telecommunications, and imaging companies. Shortly afterwards, a minor revision

504-456: A built-in GPS receiver that stores the location information in the Exif header when a picture is taken. Some other cameras have a separate GPS receiver that fits into the flash connector or hot shoe . Recorded GPS data can also be added to any digital photograph on a computer, either by correlating the time stamps of the photographs with a GPS record from a hand-held GPS receiver or manually by using

567-407: A built-in GPS receiver that stores the location information in the Exif header when a picture is taken. Some other cameras have a separate GPS receiver that fits into the flash connector or hot shoe . Recorded GPS data can also be added to any digital photograph on a computer, either by correlating the time stamps of the photographs with a GPS record from a hand-held GPS receiver or manually by using

630-496: A map or mapping software. Some cameras can be paired with cellphones to provide the geolocation. The process of adding geographic information to a photograph is known as geotagging . Photo-sharing communities like Panoramio , locr or Flickr equally allow their users to upload geocoded pictures or to add geolocation information online. Exif data are embedded within the image file itself. While many recent image manipulation programs recognize and preserve Exif data when writing to

693-496: A map or mapping software. Some cameras can be paired with cellphones to provide the geolocation. The process of adding geographic information to a photograph is known as geotagging . Photo-sharing communities like Panoramio , locr or Flickr equally allow their users to upload geocoded pictures or to add geolocation information online. Exif data are embedded within the image file itself. While many recent image manipulation programs recognize and preserve Exif data when writing to

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756-434: A modified image, this is not the case for most older programs. Many image gallery programs also recognise Exif data and optionally display it alongside the images. Software libraries, such as libexif for C and Adobe XMP Toolkit or Exiv2 for C++ , Metadata Extractor for Java , PIL/Pillow for Python , LEADTOOLS or ExifTool for Perl , parse Exif data from files and read/write Exif tag values. The Exif format has

819-434: A modified image, this is not the case for most older programs. Many image gallery programs also recognise Exif data and optionally display it alongside the images. Software libraries, such as libexif for C and Adobe XMP Toolkit or Exiv2 for C++ , Metadata Extractor for Java , PIL/Pillow for Python , LEADTOOLS or ExifTool for Perl , parse Exif data from files and read/write Exif tag values. The Exif format has

882-515: A number of drawbacks, mostly relating to its use of legacy file structures. Since the Exif tag contains metadata about the photo, it can pose a privacy problem. For example, a photo taken with a GPS -enabled camera can reveal the exact location and time it was taken, and the unique ID number of the device - this is all done by default - often without the user's knowledge. Many users may be unaware that their photos are tagged by default in this manner, or that specialist software may be required to remove

945-515: A number of drawbacks, mostly relating to its use of legacy file structures. Since the Exif tag contains metadata about the photo, it can pose a privacy problem. For example, a photo taken with a GPS -enabled camera can reveal the exact location and time it was taken, and the unique ID number of the device - this is all done by default - often without the user's knowledge. Many users may be unaware that their photos are tagged by default in this manner, or that specialist software may be required to remove

1008-457: A segment header consisting of the null-terminated string spelling "JFIF" in ASCII followed by a byte equal to 0, and specifies that this must be the first segment in the file, hence making it simple to recognize a JFIF file. Exif images recorded by digital cameras generally do not include this segment, but typically comply in all other respects with the JFIF standard. The JPEG standard used for

1071-471: A sequence of markers or marker segments (for details refer to JPEG, Syntax and structure ). The markers are defined in part 1 of the JPEG Standard. Each marker consists of two bytes: an FF byte followed by a byte which is not equal to 00 or FF and specifies the type of the marker. Some markers stand alone, but most indicate the start of a marker segment that contains data bytes according to

1134-546: A way to formally cite it in standard publications and improve its editorial quality. It was published by ECMA in 2009 as Technical Report number 98 to avoid loss of the historical record, and it was formally standardized by ITU-T in 2011 as its Recommendation T.871 and by ISO/IEC in 2013 as ISO/IEC 10918-5, The newer publications included editorial improvements but no substantial technical changes. Exchangeable image file format Exchangeable image file format (officially Exif , according to JEIDA/JEITA/CIPA specifications)

1197-562: Is JFIF compliant or not. As time went by, C-Cube was restructured (and eventually devolved into Harmonic , LSI Logic , Magnum Semiconductor , Avago Technologies , Broadcom , and GigOptix, GigPeak, etc), and lost interest in the document, and the specification had no official publisher until it was picked up by Ecma International and the ITU-T/ISO/IEC Joint Photographic Experts Group around 2009 to avoid it being lost to history and provide

1260-681: Is a standard that specifies formats for images , sound , and ancillary tags used by digital cameras (including smartphones ), scanners and other systems handling image and sound files recorded by digital cameras. The specification uses the following existing encoding formats with the addition of specific metadata tags: JPEG lossy coding for compressed image files, TIFF Rev. 6.0 ( RGB or YCbCr ) for uncompressed image files, and RIFF WAV for audio files (linear PCM or ITU-T G.711 μ-law PCM for uncompressed audio data, and IMA - ADPCM for compressed audio data). It does not support JPEG 2000 or GIF encoded images. This standard consists of

1323-681: Is a standard that specifies formats for images , sound , and ancillary tags used by digital cameras (including smartphones ), scanners and other systems handling image and sound files recorded by digital cameras. The specification uses the following existing encoding formats with the addition of specific metadata tags: JPEG lossy coding for compressed image files, TIFF Rev. 6.0 ( RGB or YCbCr ) for uncompressed image files, and RIFF WAV for audio files (linear PCM or ITU-T G.711 μ-law PCM for uncompressed audio data, and IMA - ADPCM for compressed audio data). It does not support JPEG 2000 or GIF encoded images. This standard consists of

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1386-531: Is an ISO standard , originally created by Adobe Systems Inc. , for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets. IPTC was developed in the early 1990s by the International Press Telecommunications Council (IPTC) to expedite the international exchange of news among newspapers and news agencies. Not all devices use every available metadata field in

1449-425: Is an ISO standard , originally created by Adobe Systems Inc. , for the creation, processing and interchange of standardized and custom metadata for digital documents and data sets. IPTC was developed in the early 1990s by the International Press Telecommunications Council (IPTC) to expedite the international exchange of news among newspapers and news agencies. Not all devices use every available metadata field in

1512-473: Is borrowed from TIFF files. On several image specific properties, there is a large overlap between the tags defined in the TIFF , Exif, TIFF/EP , and DCF standards. For descriptive metadata, there is an overlap between Exif, IPTC Information Interchange Model and XMP info, which also can be embedded in a JPEG file. The Metadata Working Group has guidelines on mapping tags between these standards. When Exif

1575-423: Is borrowed from TIFF files. On several image specific properties, there is a large overlap between the tags defined in the TIFF , Exif, TIFF/EP , and DCF standards. For descriptive metadata, there is an overlap between Exif, IPTC Information Interchange Model and XMP info, which also can be embedded in a JPEG file. The Metadata Working Group has guidelines on mapping tags between these standards. When Exif

1638-575: Is dated 11 July 2003, but was released in September 2003 following the release of DCF 2.0. Version 2.3 was released on 26 April 2010, and revised to 2.31 in July 2013 and revised to 2.32 on 17 May 2019, was jointly formulated by JEITA and CIPA . The latest version, 3.0, was released in May 2023, and brings, among other things, support for UTF-8 to allow text data in non-ASCII encoding. The Exif tag structure

1701-418: Is dated 11 July 2003, but was released in September 2003 following the release of DCF 2.0. Version 2.3 was released on 26 April 2010, and revised to 2.31 in July 2013 and revised to 2.32 on 17 May 2019, was jointly formulated by JEITA and CIPA . The latest version, 3.0, was released in May 2023, and brings, among other things, support for UTF-8 to allow text data in non-ASCII encoding. The Exif tag structure

1764-604: Is defined in version 2.3 as "a tag used to record fractions of seconds for the DateTime tag;" the SubsecTimeOriginal and SubsecTimeDigitized fields are defined similarly. The subsecond tags are of variable length, meaning manufacturers may choose the number of ASCII-encoded decimal digits to place in these tags. For DateTime = 2000:01:01 00:00:00 , the actual time with various subsecond values would be: The standard does not specify which particular event during

1827-482: Is defined in version 2.3 as "a tag used to record fractions of seconds for the DateTime tag;" the SubsecTimeOriginal and SubsecTimeDigitized fields are defined similarly. The subsecond tags are of variable length, meaning manufacturers may choose the number of ASCII-encoded decimal digits to place in these tags. For DateTime = 2000:01:01 00:00:00 , the actual time with various subsecond values would be: The standard does not specify which particular event during

1890-537: Is employed for JPEG files, the Exif data are stored in one of JPEG's defined utility Application Segments , the APP1 (segment marker 0xFFE1), which in effect holds an entire TIFF file within. When Exif is employed in TIFF files (also when used as "an embedded TIFF file" mentioned earlier), the TIFF Private Tag 0x8769 defines a sub-Image File Directory (IFD) that holds the Exif specified TIFF Tags. In addition, Exif also defines

1953-435: Is employed for JPEG files, the Exif data are stored in one of JPEG's defined utility Application Segments , the APP1 (segment marker 0xFFE1), which in effect holds an entire TIFF file within. When Exif is employed in TIFF files (also when used as "an embedded TIFF file" mentioned earlier), the TIFF Private Tag 0x8769 defines a sub-Image File Directory (IFD) that holds the Exif specified TIFF Tags. In addition, Exif also defines

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2016-416: Is rendered with the expectation of indicating rectangles by their centroid , rather than being pixel data directly, or being 'first corner and flood', etc. which is uncommon. The JPEG standard does not include any method of coding the resolution or aspect ratio of an image. JFIF provides resolution or aspect ratio information using an application segment extension to JPEG. It uses Application Segment #0, with

2079-405: Is represented by Y=16 and white by Y=235 and values outside of this range are available for signal processing "headroom" and "footroom", JFIF uses all 256 levels of the 8-bit representation, so that Y=0 for black and Y=255 for peak white. The RGB color primaries defined in JFIF via CCIR 601 also differ somewhat from what has become common practice in newer applications (e.g., they differ slightly from

2142-631: The RIFF file format used for WAV audio files and defines a number of tags for storing meta-information such as artist, copyright, creation date, and more in these files. The following table gives an example of Exif information found in a WAV file written by the Pentax Optio WP digital camera: The "MakerNote" tag contains image information normally in a proprietary binary format. Some of these manufacturer-specific formats have been decoded: The proprietary formats used by many manufacturers break if

2205-517: The RIFF file format used for WAV audio files and defines a number of tags for storing meta-information such as artist, copyright, creation date, and more in these files. The following table gives an example of Exif information found in a WAV file written by the Pentax Optio WP digital camera: The "MakerNote" tag contains image information normally in a proprietary binary format. Some of these manufacturer-specific formats have been decoded: The proprietary formats used by many manufacturers break if

2268-592: The XKeyscore program. The privacy problem of Exif data can be avoided by removing the Exif data using a metadata removal tool . Metadata Working Group was formed by a consortium of companies in 2006 (according to their web page) or 2007 (as stated in their own press release). Version 2.0 of the specification was released in November 2010, giving recommendations concerning the use of Exif, IPTC and XMP metadata in images. Extensible Metadata Platform (XMP)

2331-480: The XKeyscore program. The privacy problem of Exif data can be avoided by removing the Exif data using a metadata removal tool . Metadata Working Group was formed by a consortium of companies in 2006 (according to their web page) or 2007 (as stated in their own press release). Version 2.0 of the specification was released in November 2010, giving recommendations concerning the use of Exif, IPTC and XMP metadata in images. Extensible Metadata Platform (XMP)

2394-465: The "taking" of a picture the time tags should describe. The standard is, in fact, ambiguous. The DateTimeOriginal tag is defined as "The date and time when the original image data was generated." For an exposure—say, 30 seconds—longer than the granularity of the timestamp (one second for the DateTimeOriginal tag), the tag's time could correspond to the beginning of the exposure, the end of

2457-401: The "taking" of a picture the time tags should describe. The standard is, in fact, ambiguous. The DateTimeOriginal tag is defined as "The date and time when the original image data was generated." For an exposure—say, 30 seconds—longer than the granularity of the timestamp (one second for the DateTimeOriginal tag), the tag's time could correspond to the beginning of the exposure, the end of

2520-573: The Exif image file specification and the Exif audio file specification. Exif is supported by almost all camera manufacturers. The metadata tags defined in the Exif standard cover a broad spectrum: The Japan Electronic Industries Development Association (JEIDA) produced the initial definition of Exif. Version 2.1 of the specification is dated 12 June 1998. JEITA established Exif version 2.2 (a.k.a. " Exif Print "), dated 20 February 2002 and released in April 2002. Version 2.21 (with Adobe RGB support)

2583-521: The Exif image file specification and the Exif audio file specification. Exif is supported by almost all camera manufacturers. The metadata tags defined in the Exif standard cover a broad spectrum: The Japan Electronic Industries Development Association (JEIDA) produced the initial definition of Exif. Version 2.1 of the specification is dated 12 June 1998. JEITA established Exif version 2.2 (a.k.a. " Exif Print "), dated 20 February 2002 and released in April 2002. Version 2.21 (with Adobe RGB support)

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2646-628: The Exif standard. The following table shows Exif metadata for a photo made with a typical digital camera. Authorship and copyright information is generally not provided in the camera's output, so it must be filled in during later stages of processing. Some programs, such as Canon's Digital Photo Professional , allow the name of the owner to be added to the camera itself. In addition to the basic date and time tags ( DateTime , DateTimeOriginal , and DateTimeDigitized ), there are three corresponding "subsecond" tags: SubsecTime , SubsecTimeOriginal , and SubsecTimeDigitized . The SubsecTime tag

2709-628: The Exif standard. The following table shows Exif metadata for a photo made with a typical digital camera. Authorship and copyright information is generally not provided in the camera's output, so it must be filled in during later stages of processing. Some programs, such as Canon's Digital Photo Professional , allow the name of the owner to be added to the camera itself. In addition to the basic date and time tags ( DateTime , DateTimeOriginal , and DateTimeDigitized ), there are three corresponding "subsecond" tags: SubsecTime , SubsecTimeOriginal , and SubsecTimeDigitized . The SubsecTime tag

2772-598: The Exif tag before publishing. For example, a whistleblower , journalist or political dissident relying on the protection of anonymity to allow them to report malfeasance by a corporate entity, criminal, or government may therefore find their safety compromised by this default data collection. In December 2012, anti-virus businessman John McAfee was arrested in Guatemala while fleeing from alleged persecution in neighboring Belize . Vice magazine had published an exclusive interview on their website with McAfee "on

2835-542: The Exif tag before publishing. For example, a whistleblower , journalist or political dissident relying on the protection of anonymity to allow them to report malfeasance by a corporate entity, criminal, or government may therefore find their safety compromised by this default data collection. In December 2012, anti-virus businessman John McAfee was arrested in Guatemala while fleeing from alleged persecution in neighboring Belize . Vice magazine had published an exclusive interview on their website with McAfee "on

2898-520: The JPEG standard, applications can use APP marker segments and define an application specific meaning of the data. In the JFIF standard, the following APP marker segments are defined: They are described below. The JFIF standard requires that the JFIF APP0 marker segment immediately follows the SOI marker. If a JFIF extension APP0 marker segment is used, it must immediately follow the JFIF APP0 marker segment. So

2961-512: The MakerNote tag data is moved (i.e. by inserting or editing a tag that precedes it). The reason to edit to the Exif data could be as simple as to add copyright information, an Exif comment, etc. There are two solutions for this problem: Microsoft has implemented the last solution in Windows 10: In the Windows explorer you can change the Exif data of an image file by the properties window. Here

3024-400: The MakerNote tag data is moved (i.e. by inserting or editing a tag that precedes it). The reason to edit to the Exif data could be as simple as to add copyright information, an Exif comment, etc. There are two solutions for this problem: Microsoft has implemented the last solution in Windows 10: In the Windows explorer you can change the Exif data of an image file by the properties window. Here

3087-470: The color primaries defined in sRGB ). Moreover, CCIR 601 (before 2007) did not provide a precise definition of the RGB color primaries; it relied instead on the underlying practices of the television industry. Color interpretation of a JFIF image may be improved by embedding an ICC profile, colorspace metadata, or an sRGB tag, and using an application that interprets this information. A JFIF file consists of

3150-513: The compression coding in JFIF files does not define which color encoding is to be used for images. JFIF defines the color model to be used: either Y for greyscale, or YCbCr derived from RGB color primaries as defined in CCIR 601 (now known as Rec. ITU-R BT.601), except with a different "full range" scaling of the Y, Cb and Cr components. Unlike the "studio range" defined in CCIR 601, in which black

3213-461: The exposure, or some other time. This confusion is exacerbated for the subsecond tags, where the granularity (down to 1/10000th of a second in the examples in the standard) is shorter than many common exposure durations. As noted above, tags to specify the previously-missing timezone information were added in Exif version 2.31. These are "OffsetTime", "OffsetTimeOriginal" and "OffsetTimeDigitized". They are formatted as seven ASCII characters (including

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3276-461: The exposure, or some other time. This confusion is exacerbated for the subsecond tags, where the granularity (down to 1/10000th of a second in the examples in the standard) is shorter than many common exposure durations. As noted above, tags to specify the previously-missing timezone information were added in Exif version 2.31. These are "OffsetTime", "OffsetTimeOriginal" and "OffsetTimeDigitized". They are formatted as seven ASCII characters (including

3339-475: The following pattern: FF xx s1 s2 [data bytes] The bytes s1 and s2 are taken together to represent a big-endian 16-bit integer specifying the length of the following "data bytes" plus the 2 bytes used to represent the length. In other words, s1 and s2 specify the number of the following data bytes as 256 ⋅ s 1 + s 2 − 2 {\displaystyle 256\cdot s1+s2-2} . According to part 1 of

3402-591: The image decoding for most decoders, but poorly designed JFIF or Exif parsers may not recognise the file properly. JFIF is compatible with Adobe Photoshop 's JPEG "Information Resource Block" extensions, and IPTC Information Interchange Model metadata, since JFIF does not preclude other application segments, and the Photoshop extensions are not required to be the first in the file. However, Photoshop generally saves CMYK buffers as four-component "Adobe JPEGs" that are not conformant with JFIF. Since these files are not in

3465-465: The null terminator) denoting the hours and minutes of the offset, like +01:00 or -01:00 . The offset is "from UTC (the time difference from Universal Coordinated Time including daylight saving time) of the time of" the matching tag. The Exif specification also includes a description of FPXR (FlashPix-ready) information, which may be stored in APP2 of JPEG images using a structure similar to that of

3528-414: The null terminator) denoting the hours and minutes of the offset, like +01:00 or -01:00 . The offset is "from UTC (the time difference from Universal Coordinated Time including daylight saving time) of the time of" the matching tag. The Exif specification also includes a description of FPXR (FlashPix-ready) information, which may be stored in APP2 of JPEG images using a structure similar to that of

3591-527: The run" that included a photo of McAfee with a Vice reporter taken with a phone that had geotagged the image. The photo's metadata included GPS coordinates locating McAfee in Guatemala, and he was captured two days later. McAfee later claimed to have edited the Exif data from his phone to provide a false location. According to documents leaked by Edward Snowden , the NSA is targeting Exif information under

3654-422: The run" that included a photo of McAfee with a Vice reporter taken with a phone that had geotagged the image. The photo's metadata included GPS coordinates locating McAfee in Guatemala, and he was captured two days later. McAfee later claimed to have edited the Exif data from his phone to provide a false location. According to documents leaked by Edward Snowden , the NSA is targeting Exif information under

3717-427: The tab sheet "Details" contains some Exif data like title, subject, comments etc. and these Exif data can also be changed and stored. When the image file is saved the tag "OffsetSchema" (tag ID = 0xea1d) is added and this tag contains a signed 32 bit number. With this number the original index of "MakerNote" can be restored: Original index of "MakerNote" = Current index of "MakerNote" - Value of tag "OffsetSchema" But

3780-427: The tab sheet "Details" contains some Exif data like title, subject, comments etc. and these Exif data can also be changed and stored. When the image file is saved the tag "OffsetSchema" (tag ID = 0xea1d) is added and this tag contains a signed 32 bit number. With this number the original index of "MakerNote" can be restored: Original index of "MakerNote" = Current index of "MakerNote" - Value of tag "OffsetSchema" But

3843-445: The tag "OffsetSchema" was defined by Microsoft and it is not part of the official Exif standard. In some cases, camera vendors also store important information only in proprietary makernote fields, instead of using available Exif standard tags. An example for this is Nikon's ISO speed settings tag. Exchangeable image file format Exchangeable image file format (officially Exif , according to JEIDA/JEITA/CIPA specifications)

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3906-468: The thumbnail format as follows: with n = Xthumbnail × Ythumbnail The newer Exchangeable image file format (Exif) is comparable to JFIF, but the two standards are mutually incompatible. This is because both standards specify that their particular application segment (APP0 for JFIF, APP1 for Exif) must immediately follow the SOI marker. In practice, many programs and digital cameras produce files with both application segments included. This will not affect

3969-487: Was published — JFIF 1.01. For nearly 20 years, the latest version available was v1.02, published September 1, 1992. In 1996, RFC 2046 specified that the image format used for transmitting JPEG images across the Internet should be JFIF. The MIME type of "image/jpeg" must be encoded as JFIF. In practice, however, virtually all Internet software can decode any baseline JIF image that uses Y or YCbCr components, whether it

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