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PDF to JPEG Conversion - Convert PDF file to JPEG files (pdf2JPEG, pdftoJPEG)

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JPEG -- JPEG JFIF Extendable

The JPEG JFIF format is supported for reading, and batch writing, although not update in position. JPEG files are represented as you band (greyscale) or three band (RGB) datasets with Byte valued bands. The motive force will automatically convert images whose color space is YCbCr, CMYK or YCbCrK to RGB, unless GDAL_JPEG_TO_RGB is set to NO (YES may be the default). When color space translation to RGB is performed, the origin color space is indicated within the SOURCE_COLOR_SPACE metedata of the IMAGE_STRUCTURE domain. There is certainly no support for georeferencing information or metadata for JPEG files. But if an ESRI world file exists using the .jgw, .jpgw/.jpegw or .wld suffixes, it will likely be read and used to establish the geotransform for the image. If available a MapInfo .tab file may also be employed for georeferencing. Overviews could be designed for JPEG files being an external .ovr file.

The motive force also supports the "zlib compressed mask appended to the file" approach used by several data providers to add a bitmask to recognize pixels that aren't valid data. See RFC 15 for further details. The GDAL JPEG Driver is built using the Independent JPEG Group's jpeg library. Also note that the GeoTIFF driver supports tiled TIFF with JPEG compressed tiles. In order to read JPEG images with 12-bit sample, you are able to build GDAL with its internal libjpeg (depending on IJG libjpeg-6b, with a lot more changes for 12-bit sample support), or explicitely pass --with-jpeg12=yes to configure script when building with external libjpeg. See "8 and 12 bit JPEG in TIFF" wiki page for more information. It is also possible to make use of the JPEG driver using the libjpeg-turbo, a version of libjpeg, API and ABI compatible with IJG libjpeg-6b, which uses MMX, SSE, and SSE2 SIMD instructions to accelerate baseline JPEG compression/decompression.

File Details
Although JFIF files do not possess a formally-defined header, the SOI and JFIF APP0 markers taken together act as a header in the following marker segment structure:

typedef struct _JFIFHeader
    BYTE SOI[2]; /* 00h Start of Image Marker */
    BYTE APP0[2]; /* 02h Application Use Marker */
    BYTE Length[2]; /* 04h Length of APP0 Field */
    BYTE Identifier[5]; /* 06h "JFIF" (zero terminated) Id String */
    BYTE Version[2]; /* 07h JFIF Format Revision */
    BYTE Units; /* 09h Units used for Resolution */
    BYTE Xdensity[2]; /* 0Ah Horizontal Resolution */
    BYTE Ydensity[2]; /* 0Ch Vertical Resolution */
    BYTE XThumbnail; /* 0Eh Horizontal Pixel Count */
    BYTE YThumbnail; /* 0Fh Vertical Pixel Count */
SOI is the start of image marker and always contains the marker code values FFh D8h.

APP0 is the Application marker and always contains the marker code values FFh E0h.

Length is the size of the JFIF (APP0) marker segment, including the size of the Length field itself and any thumbnail data contained in the APP0 segment. Because of this, the value of Length equals 16 + 3 * XThumbnail * YThumbnail.

Identifier contains the values 4Ah 46h 49h 46h 00h (JFIF) and is used to identify the code stream as conforming to the JFIF specification.

Version identifies the version of the JFIF specification, with the first byte containing the major revision number and the second byte containing the minor revision number. For version 1.02, the values of the Version field are 01h 02h; older files contain 01h 00h or 01h 01h.

PDF to JPEG Ripper tools Features:
PDF to JPEG supports a large number of image formats.
PDF to JPEG works and simple to use, and pdf files could be added into file list and converted fast.
Supports Password Protected PDF file conversion.
You can specify any resolution within the produced Image files.
PDF to JPEG is really a stand alone software, Adobe Acrobat and Readers NOT needed!
Supports batch conversion.
Supports produce multipage TIFF files.
Able to generate huge size of JPEG files automatically.
Supports conversion into 1, 4, 8 or 24-bit image format.
Supports for PACKBITS, CCITT FAX4, LZW, JPEG compression of TIFF images.
PDF to JPEG could be released from command line, from batch file or any other application.
PDF to JPEG supports all version of PDF files.

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