`TFPReaderPNG`
pt		CurrentLine
pt		PrevSample
pt		PreviousLine
pt		PrevLinePrevSample
pt		HandleChunk
pt		HandlePalette
pt		HandleAlpha
pt		CalcX
pt		CalcY
pt		CalcColor
pt		HandleScanLine
pt		DoDecompress
pt		DoFilter
pt		SetPalettePixel
pt		SetPalColPixel
pt		SetColorPixel
pt		SetColorTrPixel
pt		DecideSetPixel
pt		InternalRead
pt		InternalCheck
pt		InternalSize
		create
		destroy

`TFPCustomImageReader`
pt		InternalRead
pt		InternalCheck
pt		InternalSize
		Create
		ImageRead
		CheckContents
		ImageSize

`TFPCustomImageHandler`
pt		Progress
		Create