PNGWriterMBS.CloseDestination

PNGWriterMBS.Finish as string

Returns "" on any error.

PNGWriterMBS.OpenWriteDestination(file as folderitem) as boolean

Dim f As FolderItem = SpecialFolder.Desktop.Child("test.png")
Dim p As New PNGWriterMBS
Dim pic As Picture = LogoMBS(500)

If p.OpenWriteDestination(f) Then
  If p.SetRGBPicture(pic) Then
    If p.SetHeader(False, -1) Then
      If p.SetGamma(0) Then
        If p.WriteInfo Then
          If p.WriteRows Then
            If p.WriteEnd Then
              MsgBox "OK"
            End If
          End If
        End If
      End If
    End If
  End If
End If

If you pass nil for the file, the data is collected in memory and you can get it on the end using the Finish method.

See also:

• OpenWriteDestination(Path as String) as boolean

Some examples using this method:

• /Images/LargePicture/PNG Load and Save
• /Images/PNG/Filters and Interlace
• /Images/PNG/png with profile
• /Images/PNG/Write Gray image
• /Images/PNG/Write with PictureMBS

PNGWriterMBS.OpenWriteDestination(Path as String) as boolean

Dim file As FolderItem = SpecialFolder.Desktop.Child("test.png")
Dim path As String = file.NativePath

Dim p As New PNGWriterMBS
Dim pic As Picture = LogoMBS(500)

If p.OpenWriteDestination(path) Then
  If p.SetRGBPicture(pic) Then
    If p.SetHeader(False, -1) Then
      If p.SetGamma(0) Then
        If p.WriteInfo Then
          If p.WriteRows Then
            If p.WriteEnd Then
              MsgBox "OK"
            End If
          End If
        End If
      End If
    End If
  End If
End If

If you pass "" for the file, the data is collected in memory and you can get it on the end using the Finish method.

See also:

• OpenWriteDestination(file as folderitem) as boolean

PNGWriterMBS.SetAlphaData(alphas() as Integer, colors() as color) as boolean

The array can have up to 256 colors.
The color and the alpha arrays must have the same size.
Returns true on success.

PNGWriterMBS.SetAlphas as boolean

You must call SetAlphaData before.
Returns true on success.

PNGWriterMBS.SetEXIF(EXIFData as string) as boolean

Returns true on success or false on failure.

PNGWriterMBS.SetGamma(gamma as Double = 0.0) as boolean

Returns on success.

The gamma parameter defines what gamma correction is applied:
positive value: use the value as the gamma correction
zero: use default value (or value saved in file itself)
negative value: do not correct gamma

Default for Mac is 1.8 and for Windows 2.2.
If you use SRGB, the Gamma must be 2.2.

PNGWriterMBS.SetGrayPicture(pict as picture, mask as picture = nil) as boolean

This method sets width, height, type and bpc properties.
Returns true on success.

Mask can be nil.

Some examples using this method:

• /Images/PNG/Write Gray image

PNGWriterMBS.SetHeader(Interlace as boolean = false, Filter as Integer = -1, Compression as Integer = -1) as boolean

Interlace is true the Adam7 interlacing is used.
FilterType specifies the filter:

const PNG_NO_FILTERS	= 0
const PNG_FILTER_NONE	= 8
const PNG_FILTER_SUB	= 16
const PNG_FILTER_UP	= 32
const PNG_FILTER_AVG	= 64
const PNG_FILTER_PAETH	= 128
const PNG_FILTER_ALL	= 248

Compression can be between 0 (none) to 9 (max). Default is 6. Value -1 means the plugin will not change from default of PNG library. Normally you have no better compression for setting higher than 6, but only burn more CPU power.

PNGWriterMBS.SetICCProfile(name as string, CompressionType as Integer, Profile as string) as boolean

Name is the profile name as an ASCII string.
CompressionType is always 0 (PNG_COMPRESSION_TYPE_BASE).

Some examples using this method:

• /Images/PNG/png with profile

PNGWriterMBS.SetPalette as boolean

Returns true on success.

PNGWriterMBS.SetPaletteData(colors() as color) as boolean

The array can have up to 256 colors.
Returns true on success.

PNGWriterMBS.SetPalettePicture(pict as picture) as boolean

You need to define the color palette before calling this method.

This method sets width, height, type and bpc properties.
Returns true on success.

PNGWriterMBS.SetResolution(ResolutionHorizontal as Integer, ResolutionVertical as Integer, Unit as Integer) as boolean

Unit is ResolutionUnknown, ResolutionMeter or ResolutionDPI.
Internally the PNG saves only in dots per meter, so the plugin converts DPI to DPM for you.

PNGWriterMBS.SetRGBPicture(pict as picture, mask as picture = nil) as boolean

// Write a RGBA PNG file
dim current as Picture = LogoMBS(500)

// create a mask
dim g as Graphics = current.Mask.Graphics
g.ForeColor = &cFFFFFF
g.FillRect 0,0,500,500
g.ForeColor = &c000000
g.FillOval 0,0,500,500

// show in window
window1.Backdrop = current

// and write to file
dim f as FolderItem = SpecialFolder.Desktop.Child("test.png")

dim p as new PNGWriterMBS

if p.OpenWriteDestination(f) then // open file
  if p.SetRGBPicture(current, current.mask) then // set picture to write
    if p.SetHeader(false, -1) then // setup file header
      if p.SetGamma(0) then // and default gamma
        if p.WriteInfo then // write file header
          if p.WriteRows then // write pixels
            if p.WriteEnd then // and write file end
              p = nil // cleanup
              f.Launch
            end if
          end if
        end if
      end if
    end if
  end if
end if

This method sets width, height, type and bpc properties.
Returns true on success.

Mask can be nil.

Some examples using this method:

• /Images/PNG/Filters and Interlace

PNGWriterMBS.SetRows(rows() as memoryblock) as boolean

The memory is not copied, so keep the array alive!
This method sets height. You need to set width, bpc, type and rowbytes.
Returns true on success.

Some examples using this method:

• /Images/PNG/Write with PictureMBS

PNGWriterMBS.SetsRGB(intent as Integer) as boolean

Possible values:

const PNG_sRGB_INTENT_PERCEPTUAL	= 0
const PNG_sRGB_INTENT_RELATIVE	= 1
const PNG_sRGB_INTENT_SATURATION	= 2
const PNG_sRGB_INTENT_ABSOLUTE	= 3

Some examples using this method:

• /Images/PNG/png with profile

PNGWriterMBS.WriteEnd as boolean

Returns true on success.

Do not call if you use WriteRows.

Some examples using this method:

• /Images/LargePicture/PNG Load and Save
• /Images/PNG/Filters and Interlace
• /Images/PNG/png with profile
• /Images/PNG/Write Gray image
• /Images/PNG/Write with PictureMBS

PNGWriterMBS.WriteInfo as boolean

Returns true on success.

Do not call if you use WriteRows.

Some examples using this method:

• /Images/LargePicture/PNG Load and Save
• /Images/PNG/Filters and Interlace
• /Images/PNG/png with profile
• /Images/PNG/Write Gray image
• /Images/PNG/Write with PictureMBS

PNGWriterMBS.WriteRow(row as memoryblock)

The data must be in the RGBA format with one byte per value.
(4 bytes per Pixel)

Returns true on success.

Do not call if you use WriteRows.

Some examples using this method:

• /Images/LargePicture/PNG Load and Save
• /Images/PNG/png with profile

PNGWriterMBS.WriteRows as boolean

// Write a RGB PNG file
dim current as Picture = LogoMBS(500)
dim f as FolderItem = SpecialFolder.Desktop.Child("test.png")

dim p as new PNGWriterMBS

if p.OpenWriteDestination(f) then // open file
  if p.SetRGBPicture(current) then // set picture to write
    if p.SetHeader(false, -1) then // setup file header
      if p.SetGamma(0) then // and default gamma
        if p.WriteInfo then // write file header
          if p.WriteRows then // write pixels
            if p.WriteEnd then // and write file end
              p = nil // cleanup
              f.Launch
            end if
          end if
        end if
      end if
    end if
  end if
end if

If you call this method, you need to call SetRGBPicture or SetPalettePicture before and you can't call WriteInfo, WriteRow and WriteEnd.

Some examples using this method:

• /Images/PNG/Filters and Interlace
• /Images/PNG/Write Gray image
• /Images/PNG/Write with PictureMBS