2021-09-12 21:54:38 +02:00

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JPEG Component Library Version 1.5 Release Notes
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This is version 1.5 of MWA Software's popular JPEG Component Library.
New in this release:
1. This release is primarily for Delphi 4 support and to ensure a common
software base is maintained.
2. Two new methods "LoadPictureFromResource" and "LoadPictureFromResID"
are provided so that JPEG images can be packaged with a program as
resources and then loaded at run-time. This can save considerable space
compared with loading an image into TImage at run-time. See the help for
information on how to use this feature and the Viewer Demo application,
which includes a JPEG resource in its about box.
3. The Delphi 3 version should now install into the IDE without
generating a "A Device Attached to the System is not Working" error
message. This was due to the components having been compiled on a system
with Quick Reports Professional installed. This error message was
experienced by users that used the standard version shipped by Borland.
New features in Version 1.4:
1. Support for C++Builder 3.0. The component library now also supports
C++Builder 3.0. The functionality is identical to the other versions
and a common source base is still maintained.
2. No DLL required for Delphi 3, and all versions of C++Builder.
Version 1.3 required a separate dll for the JPEG compression software.
This is no longer true for Delphi 3 and C++Builder. By default the
JPEG software is linked into your program - dll support is still
available as a command line option.
3. Dynamic dll loading. The Delphi 1 and Delphi 2 versions now load
the JPEG dll dynamically. This enables a more meaningful error message
to be returned if the library cannot be found. The version 1.3 static
load is still available as an option.
4. A new visual component - TDBJPEGImage has been provided. This is a
data aware descendant of TImage that stores images in a database blob
field using JPEG compression.
5. Quick Reports support: with Quick Reports version 1, the
TDBJPEGImage may be included on a report. For version 2, a new
component TQRJPEGImage is provided so that you can print JPEG images
direct from a database.
Bug Fixes:
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1. Parameters to TStream.Seek in TJPEGCompressor.SkipInputBytes now
the correct way round :( Why didn't Borland make the "ORigin"
parameter an enumerated type then this typo would have been a compile
time error!
2. The error code returned from PlayEnhMetaFile is now returned in the
error messsage
3. The decompressor now has a property (ColoursIn8bitMode) that allows
the user to specify the actual numbers of discrete colours in the
image when decoding to a 256 colour image. This used to be 256.
However, a lower number can avoid a colour cast especially with Blank
and White images encoded as full colour images. The default is now 64.
4. When the buffer size is changed the buffer will now be freed and
reallocated.
5. An event handler for warning messages has been added.
6. You should now be able to correctly save JPEG images when working
in the IDE and want to save an image as a JPEG at design time (but
only when the image was loaded from a JPEG source - the IDE cannot be
used to convert JPEG's to bitmaps, but it can be used to convert from
JPEGs to bitmaps.
7. OnProgressReport now spelt correctly! Note that uses upgrading from
earlier versions will experience an error message when loading
projects that use the JPEG Component Library reporting that the mis-
spelt property name cannot be found. Ignore this error and manually
direct the "OnProgressReport" to its event handler.