I have a PDF file that consists of the following image:
I used this image in a latex document in overleaf. The original file is 14MB large so it took overleaf some time to load it. Surprisingly, the loading sequence is such a beautiful video that I would like to make a movie out of the layers of this pdf image. I recorded my screen to get a preliminary version of this movie, but you can see that the video is not perfect and especially at the end the video it is quite far from being smooth.
You can find both files (original PDF file of the coils & the video recorded from screen) here: Documents
Is there an easy way to transform the layers of this PDF image into a movie?
I guess the first question is how can I extract the different layers of this PDF image?
Thank you very much in advance,
Jimmy
Related
I have a PDF file which is made of photographs of a book connected in a single PDF file. I'm trying to convert it back to single images in PNG format, every tool I tried asks me to set DPI which alters the size of resulting images, is there a way to get images of the exact same pixel size the original images were?
Most PDFs of books contain a single image per page and depending on the scanner these images can basically be in three different formats: JPEG, JPEG2000 or TIFF. JPEG2000 is rarely used, so your PDF probably contains JPEG and/or TIFF images.
The good thing about JPEG (and JPEG2000) images is that they can be embedded as-is into a PDF! So you can extract the images as they are stored in the PDF. With TIFF this is also sometimes possible (but I don't think always...).
As mentioned by Tim Roberts you should try using pdfimages or hexapdf images to view and extract the images stored in the PDF. This will give you the best result.
I am stucked by a video processing feature, Specifically, upload an image and then generate a video based on various video templates.
Here are the video templates:
http://video-static.biku8.com/data/video/template/3286012076458048/7437ab55-2e83-4a36-9046-5708fcddf4c1.mp4
http://video-static.biku8.com/data/video/template/3274256089907264/ae8fa3f7-6c9c-45ca-810f-48db92cc14cb.mp4
http://video-static.biku8.com/data/video/template/3213894231425088/bf107d439b9043a58c1ea0ba26f811db_template.mp4
...
As shown in the video templates above, I just need to upload a photo to generate a great video.
My question
What is the specific idea for implementing this video?
Which third-party libraries are needed? (ffmpeg, opencv)
PS: I am using dlib and opencv for face recognition. I can generate face image, but I don't know how to insert face image into the correct position of these template videos.
I would suggest you to follow the below 3 steps
Load the template video by opencv, you can access the video frame by frame
Modify each frame, one by one.
Save frame to video stream writer
Regarding step 2, actually, you must copy the uploaded image to the each frame by a mask (the pixel from source image would be copied to destination image if its coordinate on the mask is non-black). The mask could be defined by a list of points OR by an image. You should pre-define a mask for each frame in a file. Then load the mask for each frame and copy.
How to read video, save video OpenCV read-write Video
How to insert image to another image Copy non rectangular ROI
Generating videos like them are all not easy tasks. I recommend to use Adobe After Effects or other video creating software (with some scripts and actions) if you don't need to generate it by a single program or program language.
Then, I answer them below when you need to generate it by programatically.
For the first one, you should recognize faces and bones. So you should use OpenCV. ( I recommend to use tools like OpenFrameworks or TouchDesigner and so on. )
For the second one, I don't know what you exactly want, but if you want to recognize the position of the bottle dynamically, you have to use deep learning or other way to detect it. Then you may need TensorFlow or OpenCV. ( If you just want to merge layers, you can use ffmpeg etc. )
For the last one, you should split the video frame into the boxes, then you have to control. I think there are many ways to implement this. I may use OpenFrameworks, TouchDesigner, vvvv, or Processing.
I think using ffmpeg for them is not recommended. This tool is not the best for generating complicated video. But ffmpeg will do good, for example if you just merge two videos with alpha.
I have been looking for a way to convert a sequence of PNGs to a video. There are ways to do that using the CONCAT function within FFmpeg and using a script.
The problem is that I want to show certain images longer than others. And I need it to be accurate. I can set a duration (in seconds) in the script file. But I need it to be frame-accurate. So far I have not been successful.
This is what I want to make:
Quicktime video with transparancy (Prores4444 or other codec that supports transparancy + alpha channel)
25fps
This is what I have: [ TimecodeIn - TimecodeOut in destination video ]
img001.png [0:00:05:10 - 0:00:07:24]
img002.png [0:00:09:02 - 0:00:12:11]
img003.png [0:00:15:00 - 0:00:17:20]
...
img120.png [0:17:03:11 - 0:17:07:01]
Of course this is not the format of the script file. Just an idea about what kind of data I am dealing with. The PNG-imagefiles are subtitles I generate elsewhere in my application. I would like to be able to export the subtitles as a transparent movie that I can easily import in my video editing software.
I also have been thinking of using blank transparent images I will use as spacers, between the actual subtitle images.
After looking around I think this might help:
On the FFMPEG site they explain about making a timed slideshow
In the Concat demuxer section they talk about making a slideshow, based on a text file, with references to the image files and the duration of the image.
So, I create all the PNG images I need. These images have the subtitle text. Each image holds one subtitle page.
For the moments I want to hide the subtitle, I use a blank PNG.
I generate a text file as explained on the FFMPEG website.
This text file will reference to all the PNGs. For the duration I just calculate the outcue - incue. Easy... I think...
I'm trying to create a small PDF file, embedding one optimized PNG image displayed as a header and footer on a 3 page PDF (same image must appear 6x in the PDF)
My optimized PNG image is only 2.3KB. It looks very sharp.
Failed with libreoffice
When I insert just one instance of the 2.3KB PNG image into a Libreoffice Writer doc containing only text, then export as PDF I can see that the image gets re-compressed to JPG and the resulting PDF file grows by about 40KB after adding the image. It also loses quality, the PNG also gets JPG fuzzy edges.
If I right click the image and select compression, there is no way to disable recompressing the image (it's already optimized better than libreoffice could do it) I've tried setting a compression level of 0,1,9 etc. Choosing JPG, no resize, lossless, etc but there was no improvement.
Failed with wkhtmltopdf
I also tried making a test page and used wkhtml2pdf but it did the same thing. Adding the low quality flag made no difference.
PDF Spec suggests PNG is supported?
From skimming the PDF spec, it looks like PNG images are supported.
Even plain text PDF files are surprisingly large
The disappointing thing is also when I take a 7KB HTML file which is basically just <html><body><p>foo...</p><p>bar...</p> (only about 15 paragraphs) with no CSS. The resulting 2 page PDF file is 30KB. Why should a 7kb (almost plain text) file become 30kb as a PDF?
Suggestions?
Can someone please suggest how to make a small PDF file in Linux?
I need to include 7KB of text and repeat one PNG image 6 times.
Manually or programatically. I'll take whatever I can get at this point.
PDF Spec suggests PNG is supported?
PNG isn't supported per se; PDF allows embedding JPEG images as-is, but not PNG images. PDF does borrow a set of features of the PNG format, however.
rinohtype (full disclosure: I'm the author) tries to embed as much as possible from PNG images as-is into the PDF. This does involve some bit-juggling to separate the alpha channel from the color data for example, but no reencoding of the image is performed. It does not (yet) support interlaced PNGs.
rinohtype should be able to do what you want to achieve. But please note that it currently is in a beta stage, so you might encounter some bugs.
Even plain text PDF files are surprisingly large
To keep the PDF size as small as possible, make sure not to embed/subset any of the fonts. Use only the fonts from the base 14 PDF fonts which are provided by PDF readers.
What you want is certainly achievable. Regarding the image quality, I would recommend making your image twice the size that you want it to actually display at in the PDF to keep it looking sharp.
As to the size, I've just modified a test in my PDF writer module (WIP..) to include a 7.2K png, 200px x 70px, in a PDF twice and the PDF came out at 6.8K 8). There's not much text included, but more text will only add what it's worth + a small percentage.
You can see the module and original test here.. https://github.com/DoccaPDF/docca-pdf-writer/blob/master/src/tests/writer.js#L40
That test adds ~112K of images to the PDF and results in a 103K PDF.
Of course not all images are created equal so you milage may vary..
*the images are only actually added to the PDF once, but are displayed multiple time.
Is it possible to control the thumbnail size from thumbnail.cgi? Or is this extracted from the EXIF thumbnail in the main image?
In the browser example (the last 2 images at the bottom of the last tutorial page) they suggest that different size files can be generated and downloaded
How is this achieved?
I was looking at LUA scripting on a file write, but not really sure where to start with that.
Any help much appreciated.