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Tilman Hausherr commented on PDFBOX-4137: ----------------------------------------- {quote}is it best to attach a full patch every time, or incremental one {quote} Hard to tell. Most people post a complete new patch, but small one like you did has the advantage that I can see the changes. > Allow subsampled/downscaled rendering of images, and rendering subimages > ------------------------------------------------------------------------- > > Key: PDFBOX-4137 > URL: https://issues.apache.org/jira/browse/PDFBOX-4137 > Project: PDFBox > Issue Type: Improvement > Components: Rendering > Affects Versions: 2.0.8 > Reporter: Itai Shaked > Priority: Minor > Fix For: 2.0.9, 3.0.0 PDFBox > > Attachments: 0001-Image-render-subsample.patch, > 0001-Image-rendering-subsampling-removed-metadata-options.patch, > 0001-Image-subsampling-revision-2.patch, 067445.pdf, PDFBOX-1841.pdf, > PDFJS-4575-noimagedim.pdf, image_rendering_subsampling_hack.patch, > large-jpeg.pdf > > > Suggested/contributed change to allow subsampling of images and rendering > sub-regions of images. > The need arises from having very large images which are highly compressed > (usually JPEG or JBIG2). The current implementation decodes the entire image > into memory at full resolution, even if rendering is done at a much lower > resolution. > Since the change required augmenting the way Filters work (to allow > partial/subsampled decoding), it also includes a partial fix for PDFBOX-3340. > > > This change introduces "DecodeOptions" which are currently only applicable > for images. They include requesting only metadata (for PDImageXObject's > repair method), subsampling and sub-region (similar to > javax.imagio.ImageReadParam). > Since not all filters can or do honor (use) the options, the DecodeOptions > class contains a flag. Filters that honor the options (subsample / decode > only requested region) set it to true. If the flag is false, the subsampling > or cropping should be done after decoding, to ensure consistency. > PageDrawer was modified so it uses subsampling based on the ratio of the > desired output to the original image. > -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@pdfbox.apache.org For additional commands, e-mail: dev-h...@pdfbox.apache.org