class JPEGTransformationMBS
class, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: A class to wrap the jpegtran utility.
Notes:
Although rotating and flipping data expressed as DCT coefficients is not hard, there is an asymmetry in the JPEG format specification for images whose dimensions aren't multiples of the iMCU size. The right and bottom image edges are padded out to the next iMCU boundary with junk data; but no padding is possible at the top and left edges. If we were to flip the whole image including the pad data, then pad garbage would become visible at the top and/or left, and real pixels would disappear into the pad margins --- perhaps permanently, since encoders & decoders may not bother to preserve DCT blocks that appear to be completely outside the nominal image area. So, we have to exclude any partial iMCUs from the basic transformation.

Transpose is the only transformation that can handle partial iMCUs at the right and bottom edges completely cleanly. Mirror horizontal can flip partial iMCUs at the bottom, but leaves any partial iMCUs at the right edge untouched. Similarly mirror vertical leaves any partial iMCUs at the bottom edge untouched. The other transforms are defined as combinations of these basic transforms and process edge blocks in a way that preserves the equivalence.

The "trim" option causes untransformable partial iMCUs to be dropped; this is not strictly lossless, but it usually gives the best-looking result for odd-size images. Note that when this option is active, the expected mathematical equivalences between the transforms may not hold. (For example, -rot 270 -trim trims only the bottom edge, but -rot 90 -trim followed by -rot 180 -trim trims both edges.)

We also offer a "force to grayscale" option, which simply discards the chrominance channels of a YCbCr image. This is lossless in the sense that the luminance channel is preserved exactly. It's not the same kind of thing as the rotate/flip transformations, but it's convenient to handle it as part of this package, mainly because the transformation routines have to be aware of the option to know how many components to work on.

JPEGTransformationMBS.close
method, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.4, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: The destructor.
Notes:
There is no need to call this method except you want to free all resources of this object now without waiting for Realbasic to do it for you.
(e.g. some Realbasic versions crash on Windows if there are plugin objects not closed.)

JPEGTransformationMBS.CopyOption as Integer
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: What to copy from the meta information.
Notes:
Values:

JCOPYOPT_NONE	0	copy no optional markers
JCOPYOPT_COMMENTS	1	copy only comment (COM) markers
JCOPYOPT_ALL	2	copy all optional markers

(Read and Write property)

JPEGTransformationMBS.DebugLevel as Integer
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: The debug level for the jpeg library.
Notes: (Read and Write property)

JPEGTransformationMBS.Error(message as string)
event, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Plugin version: 8.5, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: This events reports all error messages from the jpeg library.

JPEGTransformationMBS.ErrorCode as Integer
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: The last error code reported.
Notes: (Read and Write property)

JPEGTransformationMBS.ErrorMessage as String
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: The last error message reported.
Notes: (Read and Write property)

JPEGTransformationMBS.Grayscale as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to reduce to grayscale (omit color data).
Notes:
If true the a color image is converted to grayscale.
(Read and Write property)

JPEGTransformationMBS.Info(message as string, msglevel as integer)
event, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Plugin version: 8.5, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: This events reports all information messages from the jpeg library.
Notes:
msglevel is one of:

-1:	recoverable corrupt-data warning, may want to abort.
0:	important advisory messages (always display to user).
1:	first level of tracing detail.
2,3,...:	successively more detailed tracing messages.

JPEGTransformationMBS.InputFile as Folderitem
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: The input file.
Notes:
Outputfile and Inputfile should never be identical, because this will corrupt the file.
(Read and Write property)

JPEGTransformationMBS.MaxMemoryToUse as Integer
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: Maximum memory to use.
Notes:
Unit is bytes.
(Read and Write property)

JPEGTransformationMBS.MirrorHorizonal as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to use the left-right mirror transformation.
Notes:
Only one transformation can be used.
(Read and Write property)

JPEGTransformationMBS.MirrorVertical as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to use the top-bottom mirror transformation.
Notes:
Only one transformation can be used.
(Read and Write property)

JPEGTransformationMBS.OptimizeCoding as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: Optimize Huffman table (smaller file, but slow compression)
Notes: (Read and Write property)

JPEGTransformationMBS.OutputFile as Folderitem
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: The output file.
Notes:
On Mac OS X, this function uses the short file name (31 characters).
So you may consider to save to a temporary file and rename it after the transformation was successfull.

Outputfile and Inputfile should never be identical, because this will corrupt the file.
(Read and Write property)

JPEGTransformationMBS.Progressive as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to create progressive JPEG file.
Notes: (Read and Write property)

JPEGTransformationMBS.Rotate180 as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to use the 180° clockwise rotation transformation.
Notes:
Only one transformation can be used.
(Read and Write property)

JPEGTransformationMBS.Rotate270 as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to use the 270° clockwise rotation transformation.
Notes:
Only one transformation can be used.
(Read and Write property)

JPEGTransformationMBS.Rotate90 as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to use the 90° clockwise rotation transformation.
Notes:
Only one transformation can be used.
(Read and Write property)

JPEGTransformationMBS.Transform as boolean
method, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: Runs the transformation.
Notes:
Outputfile and Inputfile should never be identical, because this will corrupt the file.

Returns only false if the file specifications are invalid.
So after true is returned you still need to check the errorcode property.

JPEGTransformationMBS.Transpose as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to transpose the image across UR-to-LL axis.
Notes:
Only one transformation can be used.
(Read and Write property)

JPEGTransformationMBS.Transverse as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to tanspose the image across UL-to-LR axis.
Notes:
Only one transformation can be used.
(Read and Write property)

JPEGTransformationMBS.Trim as Boolean
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 3.2, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: whether to drop non-transformable edge blocks.
Notes:
if true, trim partial MCUs as needed.
(Read and Write property)

JPEGTransformationMBS.Warning(message as string)
event, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Plugin version: 8.5, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: This events reports all warning messages from the jpeg library.

JPEGTransformationMBS.WarningMessage as String
property, Pictures Import and Export, MBS JPEG Plugin (JPEGRotation), class JPEGTransformationMBS, Console safe, Plugin version: 8.5, Mac OS X: Works, Windows: Works, Linux x86: Works, Feedback.

Function: The last warning message reported.
Notes: (Read and Write property)