[Lazarus] compiling PowerPDF on win32

[José Mejuto]

El 30/01/2013 12:01, silvioprog escribió:

> ps. IMHO, this is wrong:
> https://github.com/jepafi/Free-JPDF-Pascal/blob/master/libjpfpdf.pas#L1681.
> He promises to support multiple images, but internally it converts them
> all to JPEG, and this causes lose quality in some images.
> PDF supports PNG natively, but need to implement the specification
> exactly how Adobe explains. Two explains below:
>
> For JPEG:
> 1 - DCTDecode a lossy filter based on the JPEG standard; (I implemented it)
>
> For PNG:
> 1 - FlateDecode a commonly used filter based on the zlib/deflate
> algorithm (a.k.a. gzip, but not zip) defined in RFC 1950 and RFC 1951;
> introduced in PDF 1.2; it can use one of two groups of predictor
> functions for more compact zlib/deflate compression: Predictor 2 from
> the TIFF 6.0 specification and predictors (filters) from the PNG
> specification (RFC 2083);
> 2 - LZWDecode a filter based on LZW Compression; it can use one of two
> groups of predictor functions for more compact LZW compression:
> Predictor 2 from the TIFF 6.0 specification and predictors (filters)
> from the PNG specification;

Hello,

I'm working in a PDF rendering unit which currently can render very 
basic PDFs (you know, some rects, no clipping, some texts...) so any 
advance in any filter will be welcome. To generate the FlateDecode you 
can use the "ztream" unit and the TCompressionStream class (with 
ASkipHeader=false).

Simple PDFs that use filters and predictors will be welcomed also.

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