I am trying to convert a 8bpp (256) color gif to a 2bpp (4) color gif through ImageMagick.
How can i put an semi-transparent image to the output file in ImageMagick?
You can use ImageMagick's composite command.
Here are a couple links to tutorials and examples of using ImageMagick to add watermarks to your pictures:
from the ImageMagick help files
a blog example
yet another blog example
Related
I want to make a pixelate image in moviepy, I have reference the following Doc:
Moviepy: https://zulko.github.io/moviepy/ref/videofx/moviepy.video.fx.all.resize.html
And tried the following:
clip = ImageClip("source.jpg").resize(0.01).resize(100)
While it does make the video blur, it does not produce a pixelated image.
What I want to do is something like the below:
Imagemagick: How to pixelate/blur an image using ImageMagick?
However, I want to prevent using imagemagick natively if possible. Would like to know if it is possible, thanks.
Edit July 7, 2017: Downgrading to ImageMagick 6.9.5 solved this problem, which may be Cygwin-specific. I still don't know the underlying cause.
I need to extract data via OCR from images in PDF reports published by Chicago Public Schools. An example PDF is here (NB: this link downloads the file automatically rather than opening it in the browser). Here's a sample image (from PDF page 11, print page 8), extracted with pdfimages -png version 0.52.0 on Cygwin:
I'd like to crop each bar into its own file and extract the text with OCR. But when I try this with ImageMagick (version 7.0.4-5 Q16 x86_64 2017-01-25 according to convert -version), using the command convert chart.png -crop 320x600+0+0 bar.png, I get this image, with horizontal lines that interfere with OCR:
Running pdfimages to extract to PPM format first and then converting to PNG while cropping gives the same result, as does round-trip converting the extracted images to SVG format with ImageMagick's rsvg delegate, and fiddling with the PNG alpha channel changes the line's colors from gray to white or black but doesn't eliminate them. I've found a workaround of round-trip converting extracted images through JPG (introducing ringing artifacts, which I hope are irrelevant). But I don't see why I should have to do this. Incidentally, ImageMagick introduces the lines to PNGs even if I run a null conversion convert chart.png chart.png, which ought to leave the image unchanged:
I have found other complaints that PDF software adds horizontal lines to images, but none of them exactly matches this problem. A discussion thread mentions that versions of the PDF standard somehow differ in their treatment of alpha channels, but my knowledge of graphics is too poor understand the discussion fully; besides, my images get horizontal lines added after they're extracted from the PDF, because of something internal to ImageMagick. Can anyone shed some light on the causes of the grey lines?
Using the latest ImageMagick 7.0.6.0 Q16 Mac OS X, I get a good result. As mentioned above by Bonzo, the correct syntax for IM 7 is magick rather than convert. The use of convert reverts to IM 6. Also do not use magick convert either.
magick chart.png -crop 320x600+0+0 +repage bar.png
If this does not work for you, then there must have been a bug in your older version of IM 7. So you should then upgrade.
Note also the +repage is needed to remove the virtual canvas
I'm currently building a site in app engine that uploads images to google cloud storage and to complete basic manipulations I'm using python's PIL
I've been having problems with the following image which another stackoverflow member has mentioned is a palette-based PNG with transparency, which I've been reading may be a bit buggy in PIL
My question is really a back to basics one: What is the best way to convert this to an RGB format with transparent pixels set to #FFF? I've been able to get it to work through a combined RGBA then RGB paste but that seems redundant
However, for a direct conversion I'm getting a bad transparency mask i.e. using the solution from PIL Convert PNG or GIF with Transparency to JPG without
Also if anybody has ideas why the image degrades to terrible quality after conversion, that's entirely a bonus for me!
A way to do this is to first convert the file to jpg -- seems like a problem with the png encoding (or something related to that)
Check out this link that I used and got smooth conversion from transparent PNG to GIF:
Convert RGBA PNG to RGB with PIL
The function you are looking for is pure_pil_alpha_to_color_v2.
I also used for my image conversion tool PySmile:
https://github.com/vietlq/PySmile/blob/master/pysmile.py
I'd like to merge this ordinary png file:
with this gif animation:
(source: mytree.co.il)
I don't want to use css' position and Z-index, it messes up my images which are located in table cells.
If you are looking to make gif image, try GIMP. Here are steps to make gif image with GIMP.
http://www.wikihow.com/Create-an-Animated-GIF-Image-with-GIMP
Good Luck.
Extract the gif frames with a software like http://www.addictivetips.com/windows-tips/how-to-extract-frames-from-gif-animation-image/
Use photoshop, GIMP or any similar image editor to merge the background to the images. Tools like magic wands with a precise threshold might help in the matter
Put it all together into a new gif file
Good luck
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