I am currently rewriting my "old" Python-based Chatbots into golang.
One issue I came across was that I can´t convert a PDF into jpeg. Which I´d like to do so I can send it into a chat easily.
Already tried this with bimg (did not work at all) and imagemagick (gopkg.in/gographics/imagick.v3/imagick) as provided in this answer to another thread: "https://stackoverflow.com/a/47520596/7502507"
imagick.Initialize()
defer imagick.Terminate()
mw := imagick.NewMagickWand()
defer mw.Destroy()
mw.ReadImage(pdf)
mw.SetIteratorIndex(0) // This being the page offset
mw.SetImageFormat("jpg")
mw.WriteImage(image)
It does not produce a jpg at all, it just gives me the error
ERROR_POLICY: attempt to perform an operation not allowed by the security policy `PDF' # error/constitute.c/IsCoderAuthorized/408
How can I make this work? I can´t seem to edit the security settings for this.
Any help is appreciated!
I've been through the same issue and din't find any pure Golang solution.
Not a pure Golang solution, but this works flawlessly which uses cgo internally. Underlying library is Pdfium which is a C++ library, developed by Google and used in Chrome.
After a lot of research, I discovered that Pdfium was the best in class in terms of speed, robustness, license requirements and reliability.
To improve overall performance of the operation, I've ended up with this encoder as Golang's image encoders aren't geared towards performance and are slow.
Related
I am new to processing, i found it by searching for "draw with coding" , and i tried it, seems every time i modify the code, i have to stop and render again to get the final result
Is there any way to get updated graph without re-rendering? that can be much more convenient for creating simple figures.
if not, is there any alternative to processing that can draw a graph with coding?
I've used Tikz in Latex, but that is just for Latex, I want something that can let me draw a figure by coding, I've suffered enough though using software like coreldraw, it lacks the fundamental elegance of coding..
thanks alot！
Please have a look at the FluidForms libraries.
easy to setup
documentation and video tutorials
as long as you don't run into exceptions, live code comfortably
if you prefix public variables with param you also get sliders for free :)
Do check out the video tutorials, especially this one:
Also, if using Python isn't a problem I recommend having a look at:
NodeBox
Field
Python is a brilliant scripting language - which makes prototyping/'live coding' easy(although it can be compiled and it also plays nicely with c/c++) and is easy to pick up and a joy to use.
In Processing, you must re-run your program to see the changes (graphically), unless you write code to receive input from the user to dynamically adjust what you are drawing. For creating user interfaces there's for example the controlP5 library (http://www.sojamo.de/libraries/controlP5/).
It doesn't support "live coding" (at least that I know of).
You must re-run the code to see the new result.
If Live coding is what you're looking for, check out Fluxus (http://www.pawfal.org/fluxus/) or Impromptu (http://en.wikipedia.org/wiki/Impromptu_(programming_environment)
I have been working on a project to allow for batch encoding of any video to any other format,
up to now I have been looking for API that I am most comfortable with but then it occurred to me that video encoding can be heavy task and it might be better to use Language(platofrm) or API that has the highest performance, for instance encoding video in a language that doest best multi-cpu job scheduling is better than on ones that only simulate it and etc. Any comments or suggestions on this ?
Use ffmpeg/libavcodec.
You have two different routes to go here. You could do it all on your own,
DIY Approach
If you want to do batch encoding, you need powerful machines. Spin up something in the cloud.
Setup open source libraries. ffmpeg is a good start. It can handle many, but not all, kinds of formats.
Do the transcodings/format conversions.
Tip: Start with the command-line tool, and then go with the "API" offered by ffmpeg. The learning curve for the "API" approach is pretty steep.
Use Encoding APIs
Use cloud encoding API providers (there are many google'em).
They take care of all the background magic, and you just set up a configuration and go.
They are super simple to use. For example, check out this simple encoding api.
At the same time, they gave you lots of flexibility and are built to handle all the weird input/output format combinations.
Of course, this costs some money.
Conclusion
If you don't mind getting your hands "dirty", have time/patience to spare, go with the DIY approach. It's a very steep learning curve, but worth it. You will have skills at the end. But if this is something you are deploying for commercial use, I would advise against this approach. Rather, look for the cloud encoding API providers and start using them. There are many out there, pick the one you like. That way you can focus on the video encoding problems rather than others.
Full Disclosure: I work at Bitmovin, but that does not influence my answer.
I am developing a game in VB6 (plz don't ask me why :) ).
The storyboard is ready and a rough implementation is underway.
I am following a "pure-software-rendering" approach. (i.e. no DirectX, no openGL etc.)
Amongst many others, the following "serious" problems exist:
2D alpha transparency reqd. to implement overlays.
Parallax implementation to give depth-of-field illusion.
Capturing mouse-scroll events globally (as in FPS-es; mapping them to changing weapon).
Async sound play with absolute "near-zero-lag".
Any ideas anyone. Please suggest any well documented library/ocx or sample-code.
Plz do suggest solutions with good performance and as little overhead as possible.
Also, anyone who has developed any games,
and would be open to sharing her/his code would be highly appreciated.
(any well-acknowledged VB games whose source-code i can study??)
UPDATE: Here is a screen shot of GearHead Garage.
This picture ought to describe what i was attempting in words above... :)
(source: softwarepod.com)
EGL25 by Erkan Sanli is a fast open source VB 6 renderer that can render, rotate, animate, etc. complex solid shapes made of thousands of polygons. Just Windows API calls – no DirectX, no OpenGL.
(source: vbmigration.com)
VBMigration.com chose EGL25 as a high-quality open-source VB6 project (to demonstrate their VB6 to VB.Net upgrade tool).
Despite that, and despite my opinion that VB6 is often criticised too harshly, I can't help thinking there must be better options for game development in 2010?
You may want to check out the Game Programming Wiki -- it used to be "Lucky's VB Game Site" (and we're talking a LONG time ago) but all of the content (VB5/6 centric) moved to the Wiki with the addition of other languages.
It appears that much of the legacy VB6 content is still available on the site.
Have a look at DxIce : http://gamedev.digiapp.com/
I think you will find no well-acknowledged written games in VB6 for precisely the reasons you state above.
It was not designed to be a high performance language. For that you NEED to use the graphics libraries (DirectX, OpenGL) you said you didn't want to use unless you want to BitBLT everything yourself using API calls which is probably not going to get what you need.
VB6 is interpreted, outdated, and I'd be surprised if it runs on Windows 7.
I think you need to seriously re-evaluate the methodology here.
For audio playback, I have used http://www.fmod.org/ in the past. This, and other libraries like BASS, are only free for non-commercial use. I also suggest avoiding the built-in multimedia playback object.
I have a website which uses SVG for an interactive client side thingamabob. I would like to provide the option to download a PDF of the finished output. I can pass the final SVG output back to the server, where I want to convert to PDF, then return it to the client for download.
This would need to work on a headless shared linux server, where installation or compilation is either an enormous pain, or impossible. The website is PHP, so the ideal solution would be PHP, or use software that's easily installed on a shared webserver. Python, perl and ruby are available, along with the usual things you might expect on a linux box. Solutions that involve cairo, scripting inkscape, or installation more complex than 'FTP it up' are probably out. Spending large amounts of money are also out, naturally. As this is a shared server, memory and/or CPU hungry solutions are also out, as they will tend to get killed; this more or less rules out Batik.
The nearest that I've got so far is this XSL transform which I can drive from PHP and then squirt the resulting postscript through ps2pdf (which is already installed). The only problem with this is that it doesn't support SVG paths - if it did, it would be perfect.
There are a bunch or related questions on StackOverflow, all of which I've read through, but they all assume that you can either install stuff, spend money, or both.
Does anyone have an off-the-shelf solution to this, or should I just spend some downtime trying to add paths support to that XSL transform?
Thanks,
Dunc
I stumbled across TCPDF today which would have been perfect for this, had I known about it at the time. It's just a collection of pure PHP classes, no external dependencies for most things.
It can build PDF's from scratch and you can include pretty much anything you want in there, including SVG (amongst many, many other things), as shown in these examples:
http://www.tcpdf.org/examples.php
Main project page is here:
http://www.tcpdf.org/
Sourceforge page is here:
http://sourceforge.net/projects/tcpdf/
You can use Apache FOP's free Batik SVG toolkit which has a transcoder api to transform SVG to PDF.
download link
You will need to write a tiny bit of java. There are code examples here – note you will need to set the transcoder to org.apache.fop.svg.PDFTranscoder instead of Java.
You should be able to do this without installing anything on your machine – just drag the jars on there and run a script. I quote:
All other libraries needed by Batik are included in the distribution. As a consequence the Batik archive is quite big, but after you have downloaded it, you will not need anything else.
have you looked at imagemagick? I suspect you also need ghostscript to complete the loop, which might make installation difficulty and performance a problem.
I'd suggest giving princexml a try, they provide various addons (including one for PHP) and can output PDF from SVG/HTML/XML.
i have used TCPDF (http://www.tcpdf.org/) in many projects and it work in almost every use case.
Here is the example of SVG: https://tcpdf.org/examples/example_058/
and following is the code which can help you:
$pdf->ImageSVG($file='images/testsvg.svg', $x=15, $y=30, $w='', $h='', $link='http://www.tcpdf.org', $align='', $palign='', $border=1, $fitonpage=false);
$pdf->ImageSVG($file='images/tux.svg', $x=30, $y=100, $w='', $h=100, $link='', $align='', $palign='', $border=0, $fitonpage=false);
My custom homebrew photography processing software, running on 64 bit Linux/GNU, writes out PNG and TIFF files. These are to be sent to a quality printing shop to be made into fine art. Working with interior designers - it's important to get the colors just right!
The print shops usually have no trouble with TIFF and PNGs made from commercial software such as Photoshop. Even though i have the TIFF 6.0 specs, PNG specs, and other info in hand, it is not clear how to include color calibration data or implement color management system on linux. My files are often rejected as faulty, without sufficient error reports to make fixes.
This has been a nasty problem for a while for many. Even my contacts at the Hollywood postproduction studios are struggling with this issue. One studio even wanted to hire me to take care of their color calibration, thinking i was the expert - but no, i am just as blind and lost as everyone!
Does anyone know of good code examples, detailed technical information, or have any other enlightenment? Or time to switch to pure Apple?
Take a look at LittleCMS
http://www.littlecms.com/
This page has the code for applying it to TIFF
http://www.littlecms.com/newutils.htm
The basic thing you need to know is that Color profile data is something you need to store in the meta-data of the file itself.
There is a consultant called Charles Poynton who specialises in this area. I work for one of the post production studios you mention (albeit in london not hollywood), and have seen him speak on the subject a couple of times. His website contains a lot of the material he presents and you might find something of use there. He also has a book called Digital Video and HDTV Algorithms and Interfaces which is not as heavy as the title might suggest! While these resources might not answer your question directly, it might provide a spring board to other solutions.
More specifically, which libraries are you using to write the png and tif files - you mention they are homebrew, but how custom are they exactly? Postprocessing the images in an image manipulation program (such as ImageMagick or dcraw) might allow you to inject this information into the header more successfully.
Sorry, I don't have any specific answers, but maybe something that will point you a bit further in the right direction...
As a GNU/Linux user, you’ll want to consider DispcalGUI – http://dispcalgui.hoech.net/ – a GNOME-based GUI that centralizes color management, ICC profile management, and (crucially for your case) device calibration. It can talk to well-known pro- and mid-level hardware, e.g, i1, X-Rite, Spyder, etc.
But before you get into that – you say you are generating your files to spec; are you validating your output using a test suite specific to the format in question? If not, here are three to get you started:
imagetestsuite supports the well-known formats: https://code.google.com/p/imagetestsuite/w/list?can=1&q=
The Luminous* test suite is a JIRA plugin, if that’s your thing: https://marketplace.atlassian.com/plugins/com.luminouslead.plugin.jira.testsuite.LuminousTestSuite
FLOSS Decoder implementations often have one you can use, i.e. OpenJPEG – https://code.google.com/p/openjpeg/wiki/TestSuiteDocumentation
But even barring all of those, it seems like your problem is with embedded ICC data – which is two specs in one. First, there’s the host image-file format, and they all handle embedding differently (meaning the ICC data will likely look totally different when embedded in a TIFF than, say, a JPEG or WebP file). Second, there is the ICC spec itself. It is documented here: http://color.org/v4spec.xalter – and you may also want to look at the source for the aforementioned dispcalGUI, which includes a very legible and hackable ICC profile class in Python: http://sourceforge.net/p/dispcalgui/code/HEAD/tree/trunk/dispcalGUI/ICCProfile.py
Full disclosure: I have contributed to that very ICC profile class, to which I just linked in that last ¶
That’s the basics (many of which you have no doubt covered)... beyond that, if you post more information about what exactly is going wrong, I’d be interested to look it over. Good luck with it either way.
* NB. This project is unrelated to the long-standing photography website, “the Luminous Landscape”