Converting PDF to JPG like Photoshop quality - Commercial C++ / Delphi library

The Gnostice PDFtoolKit VCL may be a candidate. Convert to JPEG is one of the options.

I always recommend Graphics32 for all your image manipulation needs; you have several resamplers to choose. However, I don't think it can read PDF files as images. But if you can generate the big image yourself it may be a good choice.

Atalasoft DotImage (with the PDF rasterizer add-on) will do that (I work on PDF technologies there). You'd be working in C# (or another .NET) language:

ConvertToJpegs(string outfileStem, Stream pdf){    JpegEncoder encoder = new JpegEncoder();    encoder.Quality = 50;    int page = 1;    PdfImageSource source = new PdfImageSource(pdf);    source.Resolution = 300; // sets the rendering resolution to 200 dpi    // larger numbers means better resolution in the image, but will cost in    // terms of output file size - as resolution increases, memory used increases    // as a function of the square of the resolution, whereas compression only    // saves maybe a flat 30% of the total image size, depending on the Quality    // setting on the encoder.    while (source.HasMoreImages()) {        AtalaImage image = source.AcquireNext();        // this image will be in either 8 bit gray or 24 bit rgb depending        // on the page contents.        try {            string path = String.Format("{0}{1}.jpg", outFileStem, page++);            // if you need to resample the image, this is the place to do it            image.Save(path, encoder, null);        }        finally {            source.Release(image);        }    }}