I would like to split a large PNG file into A4 pages so they can be printed out easily.
I would like to use a Linux command line script to do this:
shell> split-into-a4-sized-pages some-big.png
I assume you have ImageMagick & pdfposter installed.
A) convert your .png to .pdf (using ImageMagick)
convert input0.png input1.pdf
B) tile your image using pdfposter:
pdfposter -s4 input1.pdf out.pdf
this command enlarges input0 exactly 4 times, print on the default A4
media, and let pdfposter determine the number of pages required.
Try using imagemagick's crop to your desired size.
Say you have a 640x962 image:
and you want to crop it into 4 320x481 images:
Use:
convert pexels-adonyi-gábor-1400172.jpg -crop 240x240+0+0 cropped.jpg
convert pexels-adonyi-gábor-1400172.jpg -crop 320x481+320+0 cropped.jpg
convert pexels-adonyi-gábor-1400172.jpg -crop 320x481+0+481 cropped.jpg
convert pexels-adonyi-gábor-1400172.jpg -crop 320x481+320+481 cropped.jpg
Now you'd have to find out how many pixels fit into an A4 page in your printer, and the dimensions of the image, and it is a very simple script from here.
Photo by Adonyi Gábor from Pexels.
You can use convert of ImageMagick to scale the image; there are probably other tools in ImageMagick to clip the image if you want.
I don't know of any ready-made command line tool to do this. Unless you use it all the time, ImageMagick may take longer to figure out the right combination of commands and options, than to write a quickie program.
An easy way, if you know Python at all, is write a few-line program using PIL (Python Imaging Library). To read an image takes one line. To extract chunks of some width and height at specified location to save as new image files, is also easy. Add a couple for loops to scan rows and columns of A4-sized chunks, and you're done.
If you don't know Python, just about all quick-to-write programming languages have a similar capability. The GD library comes to mind; it has bindings for several languages.
NetPBM's pamdice will do the splitting into multiple pages. You'll have to set the -width and -height options according to the DPI of your desired A4 images.
And you'll also have to convert the input image to netpbm format first with pngtopam:
pngtopam big.png | pamdice -outstem tile -height h -width w
That will leave you will a bunch of files called tile_x_y.ppm
Convert each one of those to PNG with pnmtopng
Related
I have used MiniMagick to compress JPEG files.
With strip function, I want to get rid of EXIF from image. So, I do:
image = MiniMagick::Image.open("my_picture.jpg")
image.strip
image.write("my_picture_small.jpg")
but sometimes the size of my_picture_small.jpg is bigger than my_picture.jpg.
However, when I don't use the strip function, like
image = MiniMagick::Image.open("my_picture.jpg")
# image.strip
image.write("my_picture_small.jpg")
my_picture_small.jpg's size is smaller.
That situation happened with some picture deal with Photoshop and in my CentOS computer, but run well with my Macbook. I don't know why stripping some information led to more storage.
Can anyone explain it?
Have found that ImageMagick will recompress image even if it with any arguments, such as
convert image.jpg new_image.jpg
new_image.jpg will be different from image.jpg more or less. If image.jpg is from a phone or camera or a image processing tools, the degree of difference is also different.
So compress images with MiniMagick or Rmagick that use ImageMagick as there system support, just do convert -strip image.jpg new_image.jpg may led to a unexpected result, avoid to use MiniMagick command if there is no need to greatly compress file.
I have a small problem, I have a set of animated gif images. I want to pick individual gif image files, and create multiple tiff images capturing individual frames.
I am looking to do it in Python/Java.
Help would be appreciated!
You can do this easily from the command-line using ImageMagick. It is available for free from here. It has bindings for Perl, C/C++, Python and lots of others. It is ready installed in many Linux distros.
Your command looks like this:
convert -coalesce input.gif %02d.tif
which will produce TIFF format output files, numbered 01.tif, 02.tif etc. according to the frame number.
You can also extract an individual frame, say frame 7, like this:
convert -coalesce input.gif[7] my_favourite.tif
or a sequence of frames, say 3-7 like this:
convert -coalesce input.gif[3-7] frames%02d.tif
Note however, that when you extract individual frames, you may get artefacts depending on how well compressed your original GIF files are - since they sometimes only store DIFFERENCES between frames, so you may be best advised to extract all frames then discard any you don't want.
What is the best way to generate the ".VTT" file and the jpg sprite attached with it for the Tooltip Thumbnails of Jwplayer (http://www.jwplayer.com/blog/building-tooltip-thumbnails-with-encodingcom/- ?
I know how to make an image sprite with php, but i dont know how to make the screenshots of each video with the time in second.. I think there must be a server tool to do all the tasks it but i cant find it.
Thanks
I wrote a script to do this task. Given a video file (MP4 or M4v), generate thumbnail images, compress into a sprite, and generate a VTT file compatible with JWPlayer tooltip thumbnails. All of the image manipulation uses tools from ffmpeg, ImageMagick, and optionally sips and optipng. The WebVTT generation part, I had to write.
You will have to install ffmpeg & imagemagick, at a minimum to use this.
Github code is here: https://github.com/vlanard/videoscripts (under sprites/).
The basic gist is:
Create a bunch of thumbnails, e.g. every 45th second from a video
ffmpeg -i ../archive/myvideofile.mp4 -f image2 -bt 20M -vf fps=1/45 thumbs/myvideofile/tv%03d.png
Resize those thumbnails to be small, e.g. 100pixels wide
sips --resampleWidth 100 thumbs/myvideofile/tv001.png thumbs/myvideofile/tv002.png thumbs/myvideofile/tv003.png
OR if sips not available, use imageMagick utility:
mogrify -geometry 100x thumbs/myvideofile/tv001.png thumbs/myvideofile/tv002.png thumbs/myvideofile/tv003.png
Get the height & width dimensions of one of the thumbnails to use as the basis of our grid coordinates, using ImageMagick utility
identify -format "%g - %f" thumbs/myvideofile/tv001.png
which returns output like :
100x55+0+0 - tv001.png
from which we parse 100 and 55 as our Width & Height, and the general geometry of each thumbnail (W, H, X, Y)
We then generate our single spritemap from the individual thumbnails. We determine the target grid size (e.g. 2x2, 8x8) to suit the number of thumbnails we generated for this video, as well as passing in the sprite geometry, using an ImageMagick utility
montage thumbs/myvideofile/tv*.png -tile 2x2 -geometry 100x55+0+0 thumbs/myvideofile/myvideofile_sprite.png
Optionally we can run an extra compression step here to make the sprite smaller
optipng thumbs/myvideofile/myvideofile_sprite.png
We then generate a VTT file based on the number of thumbnails we created, using
the interval that we used to space out the thumbnails to label each time segment, and
using the known coordinates of each consecutive image within our sprite that maps to
the associated segment.
I've developed a Ruby gem to easily create .VTT file and sprite of thumbnails.
Thanks for inspiring #randalv!
You can take a look at it here:
https://github.com/scaryguy/jwthumbs
Usage
Instantiate your video file:
movie = Jwthumbs::Movie.new("YOUR_VIDEO.mp4")
Jwthumbs::Movie.new accepts second parameter as a options hash. You can configure several stuff at the same time you instantiate your video like this:
movie = Jwthumbs::Movie.new("YOUR_VIDEO.mp4", seconds_between: 60, sprite_name: "my_sprite_name.jpg")
or after you instentiated your video, you can use Jwthumbs::Movie file to configure things:
movie = Jwthumbs::Movie.new("YOUR_VIDEO.mp4")
movie.seconds_between = 60
movie.sprite_name = "my_sprite_name.jpg"
and then to create your thumbnails and .VTT file just run this command.
movie.create_thumbs!
I know this is already a few years old but I had the same problem and found a command line tool which generates sprites pretty fast and since 1.0.6 supports WebVTT creation out of the box. The name is mt and you can check it here.
Quoting from their documentation you can use it like this:
just run mt and provide any video file as args: mt video.avi
Some of the settings can be changed through runtime flags provided
directly to mt for more information just run mt --help
Option 1 :
You can use the encoding.com's API and tell them to export vtt file too
I recommend to read "How can I create time synced thumbnails for use in JW player?" explanation from encoding.com's Knowledge base
Option 2 :
use movie thumbnailer (mtn), this is a command line tools running on UNIX, Windows systems. But you will have to write a custom script to generate the VTT file corresponding
Super fast! Thanks to FFmpeg's libavcodec.
Command line program: canbe used on remote connections to co-location servers, or used in scripts.
Batch mode: recursively search directories for movie files. Run at lower priority (nice 10 on Linux, idle on Windows) by default.
To run at normal priority use -n option.
Thumbnails are group together in one jpeg file and can be saved individually too (-I
option).
Work fine with Unicode filenames in both Linux & Windows
(might need to change the font with -f fontfile).
I am trying to convert svg image to eps using Imagemagick. I am able to convert the image using Imagemagick, but the image size is too high when compared to the original image size and the content is not displayed correctly compared to the svg.
I was just wondering this too. However, it appears that Imagemagick might not be the best tool to do this.
Imagemagick is a "raster image processor," but SVG and EPS are vector formats. So using Imagemagick will cause those images to lose information as it has to convert from a vector format, to a raster format, and then back to vector. This probably explains why the contents of your image aren't correctly displayed.
Maybe consider using Inkscape to do this conversion using the following
# Works as of Version 0.92.4
inkscape ing.svg \
-E out.eps \
--export-ignore-filters \
--export-ps-level=3
where the -E flag is short for --export-eps to export EPS files.
Source:
http://imagemagick.org/Usage/formats/#vector
https://stackoverflow.com/a/30539923/6873133
What command or series of commands could I execute from the CLI to recursively traverse a directory tree and reduce the bit-depth of all PNG files within that tree from 24bpp to 16bpp? Commands should preserve the alpha layer and should not increase the file size of the PNGs - in fact a decrease would be preferable.
I have an OSX based system at my disposal and am familiar with the find command so am really more keen to to locate a suitable PNG utility command.
Install fink
Say "fink install imagemagick" (might be "ImageMagick")
"convert -depth 16 old/foo.png new/foo.png"
If that did what you want, wrap it in a find call and be happy. If not, say "convert -help" and RTF-ImageMagick-M. :)
Optional: "fink install pngcrush" and run that as a second pass after the convert pass.
AFAIK the only PNG format that supports the alpha layer is PNG-24; Reducing the PNG to another format may require specifying a transparent color in a CLUT, which will not give you the output you want.
From the feature list on PNG's website:
8- and 16-bit-per-sample (that is, 24- and 48-bit) truecolor support
full alpha transparency in 8- and 16-bit modes, not just simple on-off transparency like GIF
... which I read to mean that anything other than PNG-24 or PNG-48 does not support full alpha transparency.