The watermark.png is too large for the video. I believed my code has scale code, but I'm not sure why the image doesn't scale down to it.
I've tried adding in scale2ref, but maybe didn't get the image reference correct.
$ffmpegCommand =''.$ffmpeg_b.' -y -i '.$video_file_full_path.' -i '.$watermark_image_full_path.' -i '.$watermark_image_full_path.' -filter_complex "scale=640:-2, scale=640:-2, overlay=10:10, overlay=170:170:enable=between(t\,5\,5+2)" -vcodec libx264 -preset '.$pt->config->convert_speed.' -crf 26 '.$video_output_full_path_360.' 2>&1';
I expected the image to scale according to the current scale=, but the image appears too large
Related
I am working with over thousands PDF files for a Sheet Music publisher.
All of these PDF files needs a preview PDF. A watermark for PDF files can easily be removed so I am asking for a true way to watermark our PDF:s in a batch operation.
PDF->Apply Watermark->JPG->Back to PDF
How can I do this? Is there a good tool for this operations?
The free route
ImageMagick can do the complete process for you, especially with the composite command's -watermark operator.
#!/bin/sh
# ImageMagick will pick the correct conversion formats based on filename suffixes, or maybe actual binary content?
InputPDF=$1
WatermarkImg=$2
OutputPDF=$3
pdfToImage=pdfToImage.png
imageWithWatermark=imageWithWatermark.png
# Convert PDF to image
convert \
-density 300 \
-trim \
"$InputPDF" \
-quality 100 \
-flatten \
-sharpen 0x1.0 \
$pdfToImage
# Add watermark to intermediate image
composite \
-dissolve 15 \
-tile \
"$WatermarkImg" \
$pdfToImage \
$imageWithWatermark
# Convert intermediate image back to PDF
convert \
$imageWithWatermark \
"$OutputPDF"
# Clean up
rm $pdfToImage $imageWithWatermark
I find the PDF to image conversion acceptable in terms of quality, though you can see some differences when looking at the before and after side-by-side, especially in how bolded glyphs seem less bold:
You can check this good post and its answers for a number of options for converting a PDF to an image, Convert PDF to image with high resolution.
I checked out PDFtoPPM, which was also highly mentioned in that thread, and I still see some degrading of the bolded fonts when converted:
Some more tiling Magick
I used this copyright symbol from Wikimedia Commons and this ImageMagick script:
#!/bin/sh
Infile="Copyright.png"
Outfile="Copyright_tiled.png"
h2=$(convert $Infile -format "%[fx:round(h/2)]" info:)
convert $Infile \
\( -clone 0 -roll +0+"$h2" \) \
+append \
-write mpr:sometile \
+delete \
-size 1224X1584 \
tile:mpr:sometile \
$Outfile
to create this staggered tiling (1224X1584 is the page size (8.5in x 11in) multiplied by 72 px/in, times 2 for a good density of tiles):
And here it is unwatermarked again
#ZachYoung I used some different image magic, also scriptable, the point is:-
Although "What's done cannot be undone" Macbeth (Act 5.1. 63-4) is very true especially within a PDF or image. We also know and expect that it too applies to any PDF (de)constructs. Thus depending on value of a forgery it will always be worth engineering a partially reversed copy, fit for scrutiny or use, but will like the watermarked copy, still not be the original, however all the same, may look almost just as good.
The Idiom implies don't bother yourself about it. Its best not done in the first place.
The nearest to best, is use a watermark exactly the same as the text outlines, like this:-
I'm trying to add the capability to render LaTeX equations to a project I'm working on. To do so, I use XeLaTeX to create a PDF file, which I then render to a (transparent) 96dpi-PNG using Ghostscript.
I'd like to have the rendered LaTeX blend in with the rest of the text (which is rendered using standard .NET GDI+ methods, but that's off-topic), but I can't get a reliably "good" text rendering: the output always looks somehow blurry or otherwise "bad".
Example:
From left to right, the same (small) PDF rendered at 96dpi with Ghostscript, Photoshop, and TexWorks (which I understand uses Ghostscript internally).
The command I use to run Ghostscript is the following:
"C:/Program Files (x86)/gs/gs9.09/bin/gswin32c.exe" \
-q -dQUIET -dSAFER -dBATCH -dNOPAUSE -dNOPROMPT \
-dMaxBitmap=500000000 -dAlignToPixels=1 -dGridFitTT=2 \
"-sDEVICE=pngalpha" -dTextAlphaBits=4 \
-dGraphicsAlphaBits=4 "-r96" -dFirstPage=1 -dLastPage=1 \
-sOutputFile="output.png" "input.pdf"
(which I actually pretty much copied from the command ImageMagick calls when converting a PDF file, but that's another story). I tried changing any of the relevant options (dAlignToPixels=0, dGridFitTT=0/1/2, dTextAlphaBits=2/4 [or without this parameter altogether]) and I even tried to render the PDF to 4 times the resolution and then downscale it, without any noticeable improvement.
Yet, I'm sure there must be some way of decently rendering the PDF with Ghostscript (since TexWorks does), although I'm unable to find it.
Any hint? The PDF is this one.
You could try to render your PDF at a higher resolution. 96dpi just isn't enough for text with 11 pt size.
If you use 192dpi and then scale the display of the resulting image to 50% (wherever you use the PNG), these parts should still appear in the same size as befor, but with a higher resolution. What used to be a 4x7 pixels 's' should now be a 8x14 pixels 's'...
Update
Ok, since my explanation seems to have been not comprehendible enough for the OP, here's the deal.
Generate a PDF file containing the word "Test", using Ghostscript. In my case, it is Ghostscript v9.10:
gs \
-o test.pdf \
-sDEVICE=pdfwrite \
-g230x100 \
-c "/Helvetica findfont \
11 scalefont \
setfont \
1 1 moveto \
(Test) show \
showpage"
From this PDF, generate 6 different images depicting the word "Test", using 6 different resolutions. The gs is still Ghostscript v9.10 (to be checked with gs -version):
for i in 1 2 3 4 5 6; do \
gs \
-o t$(( ${i} * 96 )).png \
-r$(( ${i} * 96 )) \
-sDEVICE=pngalpha \
-dAlignToPixels=1 \
-dGridFitTT=2 \
-dTextAlphaBits=4 \
-dGraphicsAlphaBits=4 \
t.pdf ; \
done
This will create the following PNGs, as confirmed by ImageMagick's identify command:
identify -format "%f : %Wx%H pixels -- %b filesize\n" t[1-9]*.png
t96.png : 31x13 pixels -- 475B filesize
t192.png : 61x27 pixels -- 774B filesize
t288.png : 92x40 pixels -- 1.1KB filesize
t384.png : 123x53 pixels -- 1.43KB filesize
t480.png : 153x67 pixels -- 1.76KB filesize
t576.png : 184x80 pixels -- 2.01KB filesize
Create a sample LaTeX document and embed the different images side by side and/or line by line. Here is my sample code:
\begin{document}
Test
\includegraphics[height=7.5pt]{t96.png}
\includegraphics[height=7.5pt]{t96.png}
\includegraphics[height=7.5pt]{t192.png}
\includegraphics[height=7.5pt]{t288.png}
\includegraphics[height=7.5pt]{t384.png}
\includegraphics[height=7.5pt]{t480.png}
\includegraphics[height=7.5pt]{t576.png}
Test\\
{}
Test <== real text
\includegraphics[height=7.5pt]{t96.png} <-- 96 dpi figure
\includegraphics[height=7.5pt]{t192.png} <-- 192 dpi figure
\includegraphics[height=7.5pt]{t288.png} <-- 288 dpi figure
\includegraphics[height=7.5pt]{t384.png} <-- 384 dpi figure
\includegraphics[height=7.5pt]{t480.png} <-- 480 dpi figure
\includegraphics[height=7.5pt]{t576.png} <-- 576 dpi figure
Test <== real text
\end{document}
Here is a screenshot (at 400% zoom) from the PDF created via LuaLaTeX from the above LaTeX code:
The line with the 8 "Test" words has actual text only in the first and the last word. The 6 words in between are images with 96, 96, 192, 288, 384, 480 and 576 dpi.
I hope you can see now clearly how scaling up your image generation to a higher resolution will result in better quality for your final PDF if you include the higher resolution images into your LaTeX code...
You are rendering text at 11 points, at 96 dpi, that works out to about 14 pixels in height which, frankly, is not a lot (and in my output the 's' is 7 pixels high by 4 wide). Looking at your output all 3 look 'blurry' and the Photoshop output looks overly bold in the capital T.
If you don't want it blurred, then don't set TextAlphaBits, or don't set it to such a high value.
I'd also suggest using the current release (9.15).
I have to change a given PDF from A4 (210mm*297mm) to 216mm*303mm.
The additional 6 mm for each dimension should be set as white border of 3mm on each side. The original content of the PDF pages should be centered on the output pages.
I tried with convert:
convert in.pdf -bordercolor "#FFFFFF" -border 9 out.pdf
This gives me exactly the needed result but I loose very much sharpness of the original images in the PDF. It is all kind of blurry.
I also checked with
convert in.pdf out.pdf
which does no changes at all but also screws up the images.
So I tried Ghostcript but did not get any result. The best approach I found so far from a German side is:
gs -sOutputFile=out.pdf -sDEVICE=pdfwrite -g6120x8590 \
-c "<</Install{1 1 scale 8.5 8.5}>> setpagedevice" \
-dNOPAUSE -dBATCH in.pdf
but I get Error: /typecheck in --.postinstall--.
By default, Imagemagick converts input PDF files into images with 72dpi. This is awfully low resolution, as you experienced firsthad. The output of Imagemagick is always a raster image, so if your input PDF was text, it will no longer be.
If you don't mind the output PDF's getting bigger, you can simply increase the ratio Imagemagick is probing the original PDF using -density option, like this:
convert -density 600 in.pdf -bordercolor "#FFFFFF" -border 9 out.pdf
I used 600 because it is the sweet spot that works well for OCR. I recomment trying 300, 450, 600, 900 and 1200 and picking the best one that doesn't get unwieldably huge.
Shifting the content on the media is not especially hard, but it does mean altering the content stream of the PDF file, which most PDF manipulation packages avoid, with good reason.
The code you quote above really won't work, it leaves garbage on the operand stack, and the PLRM explicitly states that it is followed by an implicit initgraphics which will reset all the standard parameters anyway.
You could try instead setting a /BeginPage procedure to translate the origin, which will probably work:
<</BeginPage {8.5 8.5 translate} >> setpagedevice
Note that you aren't simply manipulating the original PDF file; Ghostscript takes the original PDF file, interprets it into graphics primitives, then reassembles those primitives into a new PDF file, this has implications... For example, if an image is DCT encoded (a JPEG) in the original, it will be decompressed before being passed into the output file. You probably don't want to reapply DCT encoding as this will introduce visible artefacts.
A simpler alternative, but involving multiple processing steps and therefore more potential for problems, is to first convert the PDF to PostScript with the ps2write device, specifying your media size, and also the -dCenterPages switch, then use the pdfwrite device to turn the resulting PostScript into a new PDF file.
Instead of
-g6120x8590 \
-c "<</Install{1 1 scale 8.5 8.5}>> setpagedevice"
(which is wrong), you should use:
-g6120x8590 \
-c "<</Install{8.5 8.5 translate}>> setpagedevice"
or
-g6120x8590 \
-c "<</Install{3 25.4 div 72 mul dup translate}>> setpagedevice"
(which lets Ghostscript calculate the "3mm == 8.5pt" itself...)
I'm trying to upload hi-res PDF files to our servers, but would like to generate a smaller PDF file size so that it loads quickly on my web application by reducing the dpi resolution.
Is this something that iTextSharp can do? Or is there another free software that can achieve this?
PDF files, in general, do not have DPI. Raster images embedded in a PDF file do. What you can do, is to extract the images embedded in your PDF file, resize them to a lower resolution, and put them back in your file.
There is a chapter about this topic in the book iText in Action.
Ghostscript is Free Software (if you want), and it can downsample PDFs any way you want (well, downsample the pixel images that may be embedded on its pages).
Example commandline, which downsamples all images to 72dpi (provided they have a resolution that's more than 144dpi). I'll not use the shortest command, but I deliberately try to enumerate all potentially useful parameters, so that you can experiment:
gs \
-o downsampled.pdf \
-sDEVICE=pdfwrite \
-dColorImageDownsampleThreshold=2.0 \
-dGrayImageDownsampleThreshold=2.0 \
-dMonoImageDownsampleThreshold=2.0 \
-dColorImageDownsampleType=/Bicubic \
-dGrayImageDownsampleType=/Bicubic \
-dMonoImageDownsampleType=/Bicubic \
-dDownsampleColorImages=true \
-dDownsampleGrayImages=true \
-dDownsampleMonoImages=true \
-dColorImageResolution=72 \
-dGrayImageResolution=72 \
-dMonoImageResolution=72 \
-dAutoFilterColorImages=false \
-dAutoFilterGrayImages=false \
\
-dEncodeColorImages=true \
-dEncodeGrayImages=true \
-dEncodeMonoImages=true \
-dColorImageFilter=/DCTEncode \
-dGrayImageFilter=/DCTEncode \
-dMonoImageFilter=/CCITTFaxEncode \
input.pdf
If you want to downsample all color images (that is, also the ones from 73dpi to 144dpi), then use -dColorImageDownsampleThreshold=1.0 (Ghostscript's default is =1.5); the same goes for other *ImageDownsampleThreshold settings.
For the *ImageDownsampleTypes -- you can also experiment with values of /Average or /Subsample instead of my suggested /Bicubic. And you are of course als free to use different settings for resolution, sampling type and thresholds across the mono, gray and color image types.
Is there any easy (scriptable) way to convert a PDF with vector images into a PDF with raster images? In other words, I want to generate a PDF with the exact same (un-rasterized) text but with each vector image replaced with a rasterized version.
I occasionally read PDFs of technical articles on my Kindle, and have found that reading a PDF directly is frustrating. Thankfully, Amazon's automatic conversion of PDFs to the Kindle format does a good job of reflowing the text portions of most of PDFs I have tried. However, while raster images seem to make it through the conversion process fine, vector images get horribly mangled. It would be great if I could easily convert a PDF so that all of its vector images were rasterized.
I am interested in any possible solutions, but a Linux- or Windows-based one would be preferable.
I had a similar issue, and solved it using ImageMagics convert tool (http://www.imagemagick.org/script/index.php). That comes with linux and runs fine on Windows/Cygwin or OS X
convert -density 300 largeVectorFileFromR.pdf out.pdf
With -density 300 you control resolution (as DPI).
Downside: Text is rasterized as well, I understand that Michael does not want this.
After some days searching for some solution, based on "Remove all text from PDF file" and "How to add a picture onto an existing pdf file?" I found a (ugly) scriptable solution:
gs -o /tmp/onlytxt.pdf -sDEVICE=pdfwrite -dFILTERVECTOR -dFILTERIMAGE $INPUT_FILE && \
gs -o /tmp/graphics.pdf -sDEVICE=pdfwrite -dFILTERTEXT $INPUT_FILE && \
convert -density $DPI -quality 100 /tmp/graphics.pdf /tmp/graphics.png && \
convert -density $DPI -quality 100 /tmp/graphics.png /tmp/graphics.pdf && \
pdftk /tmp/graphics.pdf stamp /tmp/onlytxt.pdf output $OUTPUT_FILE && \
rm /tmp/onlytxt.pdf /tmp/graphics.pdf /tmp/graphics.png
were we have three variables INPUT_FILE, OUTPUT_FILE, and DPI. We split the textual and graphical contents via Ghostscript, convert the graphical image to a raster image (PNG) and join the two using pdftk.
I've been using this successfully to convert huge vector images for use in scientific papers.
Pitstop Pro v2 update 3 from Enfocus can do exactly that. It has an action called "Rasterize page content, keeping text" which works pretty well. It is a plugin to Adobe Acrobat so it requires a little more but is also available as a server solution.
It's a little complicated, but you asked for any possible solution. Furthermore this solution is not automatable.
1) Open the pdf with the vector images in Inkscape. Then select the whole image with the select tool (F1)
2) If the vector image is consistant of more than one svg graphic press Ctrl + G (Object --> Group)
3) cut the grouped svg image Ctrl + x
4) open a new InkScape Window Ctrl + n and paste the image Ctrl + v
5) choose File --> export Bitmap (Shift + Ctrl + e), maybe you want to increase the dpi
6) go back to the first InkScape window, File --> import (Ctrl + i) and choose the previously exported bitmap
7) place the bitmap to the location where the svg image was
Save the pdf and the vector image is replaced by a bitmap image.
Here's one way to solve your problem:
Step 1: Use an online PDF-to-HTML converter, like the one here:
http://www.idrsolutions.com/online-pdf-to-html5-converter/
This tool converts the PDF into a set of images and a text overlay. The vector images should be converted to raster at this point.
Step 2: Convert the HTML+images back into PDF:
http://pdfcrowd.com/#convert_by_upload+with_options
The resulting PDF will have all the vector images rasterized, and all text will remain text, so you can select, copy, etc.
Convert the pdf to djvu with https://jwilk.net/software/pdf2djvu converter. Uncheck "antialias fonts,vectors..". It will reduce file size significantly and improve document load times.
I used the following:
gswin32c -o "%2" -dFirstPage=1 -dLastPage=1 -sDEVICE=pngalpha -r72x72 -dUseCropBox -dFitPage "%1" -dBATCH -dNOPAUSE
where %1 is the input file and %2 is the output. This can be used with LaTeX, the generated PNG has the same ratio and page size as the original PDF so the relative position of the image will not change.
Note that in Linux, you may need to use gs rather than gswin32c.
You can also set the page range and then print the pages back to PDF. The downside is that the text gets rasterized as well.
inkscape is the best solution, I quickly made this rather unoptimized batch file that does exactly that and you can play with it and change options. ImageMacick convert, gs, or pdftoimages don't work as good as inkscape they either don't export the layers or export but with bad quality :
#!/bin/bash
#set -xev
ORIGINAL_FOLDER=`pwd`
JPEGS=`mktemp -d`
unzip "$1" -d "$JPEGS"
cd "$JPEGS"
# expang the pdf in pdf pages
pdftk combined_to_do.pdf burst output pg_%04d.pdf
#1) print the pdf's to pngs as they are seen with alpha, layers, transparency etc, this cannot be done by ImageMacick convert or pdftoimages
ls ./pg*.pdf | xargs -L1 -I {} inkscape {} -z --export-dpi=300 --export-area-drawing --export-png={}.png
#2) Second change to jpgs
rm *.pdf
ls ./p*.png | xargs -L1 -I {} convert {} -quality 100 -density 300 {}.jpg
#3) This to make a pdf file out of every jpg image without loss of either resolution or quality:
ls -1 ./*jpg | xargs -L1 -I {} img2pdf {} -o {}.pdf
#4) This to concatenate the pdfpages into one:
pdftk *.jpg.pdf cat output combined.pdf
#5) And last I add an OCRed text layer that doesn't change the quality of the scan in the pdfs so they can be searchable:
pypdfocr combined.pdf
cp "$JPEGS/combined_ocr.pdf" "$ORIGINAL_FOLDER/$1_ocr.pdf"
cp "$JPEGS/combined.pdf" "$ORIGINAL_FOLDER/$1.pdf"
Based on Civ Lins solution, I came up with this:
#!/usr/bin/env sh
gs -o /tmp/onlytxt.pdf -sDEVICE=pdfwrite -dFILTERVECTOR -dFILTERIMAGE $1 && \
gs -o /tmp/graphics.pdf -sDEVICE=pdfimage24 -dFILTERTEXT -r600 -dDownScaleFactor=6 $1 && \
pdftk /tmp/graphics.pdf multistamp /tmp/onlytxt.pdf output $2 && \
rm /tmp/onlytxt.pdf /tmp/graphics.pdf
(In contrast to the previous solution, it handles multipage PDFs and uses gs to directly render the rasterized image without the detour of convert.)