Monkeybread Xojo plugin - JPEGImporterMBS class

Platforms to show: All Mac Windows Linux Cross-Platform

JPEGImporterMBS class

Type	Topic	Plugin	Version	macOS	Windows	Linux	iOS	Targets
class	JPEG	MBS Images Plugin		✅ Yes	✅ Yes	✅ Yes	✅ Yes	All

Function: A class for JPEG Importing.
Example:

dim g as FolderItem
dim ji as JPEGImporterMBS
dim je as JPEGExporterMBS
dim f as FolderItem
dim m as MemoryBlock

// this code copies a JPG: CMYK or RGB

// import it
g=SpecialFolder.Desktop.Child("PICT1533.JPG")
ji=new JPEGImporterMBS
ji.File=g
ji.AllowDamaged=true
ji.CMYK=true // if it is cmyk
if ji.InitJPEG then
  do
  loop until ji.LoopJPEG<>0
  ji.FinishJPEG
end if

// export it
f=SpecialFolder.Desktop.child("PICT1533 copy.JPG")
je=new JPEGExporterMBS
je.File=f
je.Quality=75

if ji.CMYK then
  m=ji.PictureData
  je.ExportCMYK m, ji.Width, ji.Height, ji.Width*4
else
  je.Picture=ji.Picture
  je.Export
end if

Notes:
This class is not depending on any library! It works without QuickTime even on System 7, but as it contains everything needed this method is around 100 KB big!

Bases on libjpeg.

Feedback, Comments & Corrections

4 events
- event Error(message as string, ErrorCode as Integer)
- event HeadersRead as boolean
- event Info(message as string, msglevel as Integer, ErrorCode as Integer)
- event Warning(message as string, ErrorCode as Integer)
34 properties
- property AllowDamaged as boolean
- property BlockSmoothing as Boolean
- property CMYK as Boolean
- property ColorComponentCount as Integer
- property ColorSpace as Integer
- property CurrentDepth as Integer
- property data as string
- property ErrorMessage as string
- property ExifData as String
- property ExifOrientation as Integer
- property ExifThumbnail as String
- property FancyUpsampling as Boolean
- property file as folderitem
- property FileOffset as Integer
- property Height as Integer
- property HorizontalResolution as Integer
- property Mode as Integer
- property OriginalDepth as Integer
- property Path as String
- property Picture as Picture
- property PictureData as MemoryBlock
- property ProfileData as String
- property ProgressiveMode as Boolean
- property ReadExifData as Boolean
- property ReadMarkers as Boolean
- property ReadProfileData as Boolean
- property ReadXMPData as Boolean
- property ResolutionUnit as Integer
- property ScaleFactor as Integer
- property VerticalResolution as Integer
- property WarningMessage as String
- property Width as Integer
- property XMPData as String
- property YieldTicks as Integer
shared property API as String
12 methods
- method BlueTestPicture as picture
- method CleanMarkers
- method FinishJPEG
- method GreenTestPicture as picture
- method Import
- method ImportCMYK
- method InitJPEG as boolean
- method LoopJPEG as Integer
- method MarkerCount as Integer
- method MarkerItem(index as Integer) as JPEGImporterMarkerMBS
- method ReadHeader as boolean
- method RedTestPicture as picture
2 shared methods
- shared method GetJPEGVersion as String
- shared method SetAPI(API as Ptr = nil)
24 constants

Color Spaces

Constant	Value	Description
ColorSpaceCMYK	4	C/M/Y/K
ColorSpaceGrayScale	1	Gray
ColorSpaceRGB	2	red/green/blue
ColorSpaceUnknown	0	Not set.
ColorSpaceYCbCr	3	Y/Cb/Cr (also known as YUV)
ColorSpaceYCCK	5	Y/Cb/Cr/K

Orientation Constants

Constant	Value	Description
kOrientationBottomLeft	4	row 0 bottom, col 0 lhs
kOrientationBottomRight	3	row 0 bottom, col 0 rhs
kOrientationLeftBottom	8	row 0 lhs, col 0 bottom
kOrientationLeftTop	5	row 0 lhs, col 0 top
kOrientationRightBottom	7	row 0 rhs, col 0 bottom
kOrientationRightTop	6	row 0 rhs, col 0 top
kOrientationTopLeft	1	row 0 top, col 0 lhs
kOrientationTopRight	2	row 0 top, col 0 rhs

Modes

Constant	Value	Description
ModeAuto	30	Load the image into the picturedata property. Switches on import to RGB, Gray or CMYK depending on color space of JPEG file.
ModeAutoByRow	31	Load the image into the picturedata property. Switches on import to RGB, Gray or CMYK depending on color space of JPEG file.
ModeCMYK	2	Load the image into the picturedata property. The PictureData Memoryblock uses 4 bytes per pixel.
ModeCMYKbyRow	12	Same as ModeCMYK, but PictureData contains only the current row The PictureData Memoryblock uses 4 bytes per pixel.
ModeGray	3	Load the image into the picturedata property. The PictureData Memoryblock uses one byte per pixel.
ModeGraybyRow	13	Same as ModeGray, but PictureData contains only the current row The PictureData Memoryblock uses one byte per pixel.
ModePicture	0	Load the image into the picture property.
ModeRaw	20	Load the image into the picturedata property. The PictureData Memoryblock uses 1 to 4 bytes per pixel. Check the colorspace property to know which color space is used.
ModeRGB	1	Load the image into the picturedata property. The PictureData Memoryblock uses 3 bytes per pixel.
ModeRGBbyRow	11	Same as ModeRGB, but PictureData contains only the current row The PictureData Memoryblock uses 3 bytes per pixel.

This class has no sub classes.

Some examples using this class:

Blog Entries

Xojo Developer Magazine

The items on this page are in the following plugins: MBS Images Plugin.

JPEGImporterMarkerMBS - JPEGMovieMBS