Trying to convert the Image Magick convert command:
convert -size 50x50 -background white -fill black -gravity center label:Ryan test.gif
to magick++/PythonMagick. Cannot use annotate since I need to have the text auto-sized, which 'label' does. I can do
img = PythonMagick.Image('50x50', 'none')
img.backgroundColor('white')
img.fillColor('black')
img.read('label:Ryan')
img.write('test.gif')
but img.read does not allow me to specify gravity. Is there a way to do this without using subprocess or os?
Related
I want to convert multiple images into square format, filling any empty space with black. Assuming the images have a width of 1000 and a height of less than 1000 (or vice versa), I can do it like this (using PowerShell):
magick.exe convert -background black -gravity center `
-resize 1000x1000 -extent 1000x1000 `
-set filename:original '%t' '.\*.jpg' './%[filename:original]-resized.jpg'
However, I want this to work for arbitrarily sized images. I need to do something like this, which is not an actually supported syntax:
#...
-resize 'max(%w,%h)xmax(%w,%h)' -extent 'max(%w,%h)xmax(%w,%h)' `
# ...
Is there an Imagemagick syntax for what I'm trying to do?
In Imagemagick 7, use magick, not magick convert and move the input parameter to the first parameter position, i.e. magick '.\*.jpg'.
Then, to do what you want change
-resize 'max(%w,%h)xmax(%w,%h)' -extent 'max(%w,%h)xmax(%w,%h)'
to
-resize "%[fx:max(w,h)]x%[fx:max(w,h)]" -extent "%[fx:max(w,h)]x%[fx:max(w,h)]"
Let's start with a background and an overlay image:
magick convert -size 500x500! xc:red background.jpg # make a big red background
magick convert -size 100x100! xc:blue overlay.jpg # make a smaller blue overlay
To composite from right side I can use
$geom=magick convert overlay.jpg -print "+%[fx:w+50]+0" null:
magick convert background.jpg overlay.jpg -gravity northeast -geometry $geom -composite output.jpg
However, in my real project, I need to run this with various background images, whose sizes are also various. I would like the overlay to use relative size to the background instead of absolute size.
To overlaying a watermark/logo with relative dimentions, I can use:
magick background.jpg overlay.jpg -resize %[fx:t?u.w*0.9:u.w]x%[fx:t?u.h*0.9:u.h] -gravity northease -composite output.jpg
To resize overlay image by ratio and with relative position it from the right, I try:
magick background.jpg overlay.jpg -resize %[fx:t?u.w*0.1:u.w]x%[fx:t?u.h*0.1:u.h] -gravity northeast -geometry +[fx:t?u.w*0.1:u.w]+[fx:t?u.h*0.1:u.h] -composite output.jpg
But it says:
magick.exe: invalid argument for option '-geometry' '+[fx:t?u.w*0.1:u.w]+[fx:t?u.h*0.1:u.h]' at CLI arg 7 # error/operation.c/CLISimpleOperatorImage/2522.
The documentation for geometry doesn't seem to talk about this. Do you know why?
I'm using v7 on Windows
I miss the %. Correct code:
magick .\base.jpg .\logo.png -resize %[fx:t?u.w*0.1:u.w]x%[fx:t?u.h*0.1:u.h] -gravity northeast -geometry +%[fx:t?u.w*0.03:u.w]+%[fx:t?u.w*0.03:u.w] -composite output.png
See Format and Print Image Properties
The reasoning behind the %[fx:t?u.w*0.9:u.w]
From The FX Special Effects Image Operator:
u: first image in list
v: second image in list
t: index of current image (s) in list
w: width of this image
So in plain language, it means that if the image in question is the second image, whose index is one, of which the ternary conditional operator also read as true, then resize it to 90% width of the first image, else do no resize. Or else -resize option will apply to each images in an image sequence (i.e. all input images before it, but not after it).
I would like to take this logo and place it on a black background.
I am using the below script
convert -size 4000x4000 canvas:#000000 -background \#000000 background.jpg
composite rev.jpg -gravity center background.jpg output.jpg
open output.jpg
Which generates. As you can see the colours have changed and I cannot work out why?
Just set the colorspace.
composite 03wp2.jpg -colorspace srgb -gravity center background.jpg output.jpg
Possibly a colour profile or are you using CMYK for the rev.jpg?
Try this which will shorten your code:
convert rev.jpg -background black -gravity center -extent 4000x4000 output.jpg
How to create a blank new image in Imagemagick via command line?
Using -background doesn't work:
$ convert -size 800x800 -background white x.png
convert: no images defined `x.png' # error/convert.c/ConvertImageCommand/3257.
White background
convert -size 800x800 xc:white white.png
xc: used to mean "X Constant Image" but now is just a shorthand for canvas:. This means you can also use:
convert -size 800x800 canvas:white white.png
and because "white" is the default value if no color is provided, you can also use:
convert -size 800x800 xc: white.png
convert -size 800x800 canvas: white.png
Transparent background
If by "blank" you mean "transparent", just use that word as the color:
convert -size 800x800 xc:transparent transparent.png
Answer made possible by ImageMagick v6 Examples and How to create a new image?
You need to supply PNG24, PNG8 or PNG32 prefix if planning to use this canvas to layer colour images over. Without it, it creates a Grey colour space. I used 32, as I need "varying degrees of transparency for each pixel" (pixel art)
convert -size 800x800 canvas:transparent PNG32:canvas.png
For more about PNG types see this link.
I need to be able to apply watermark on an image, using either text or another image.
Getting it to work with an image was quite straight forward, using the following command:
gm composite -dissolve 15 -tile logo.png image.jpg wmark_tiled.jpg
Now, I also want to be able to use text for watermarking (in other cases). The only thing that I found close to it, is a command from ImageMagick tutorial which is the following :
convert -size 140x80 xc:none -fill grey -gravity NorthWest -draw "text 10,10 'copyrigh text'" -gravity SouthEast -draw "text 5,15 'copyright text'" miff:- | gm composite -tile - image.jpg copyrightImage.jpg
Although its not working in GM, and I would rather avoid using pipe as it causes some headaches managing it from Java.
What I thought I could do, is generate an image from a given text, and then use that image as logo.png is used on my first command. Although I cannot find how to generate an image out of text, all I find is putting text on top of an image.
Ideally I will generate a transparent image with the text, and from what I see modifying font/color etc should be quite flexible.
Any suggestions on how to achieve this, or any better solutions are welcome.
(I added imagemagick tag as the interfaces are often same/similar)
I'm not sure I fully understand your query, so apologies if I've misunderstood, but are you trying to create a transparent image, with some text in the corner? If so, would this not work?
convert -background transparent -fill grey -font Calibri -size 140x80 -pointsize 14 -gravity southeast label:'copyright text' output.png
Obviously adjusting the font, pointsize, output image name etc. That would create the following:
http://oi42.tinypic.com/14j1bvp.jpg
P.S. that was written for ImageMagick. I don't know how GM differs or whether it would still work.
To be able to get the watermark text into the same image I had to use the -annotate parameter.
So Moogle's code snippet would look like this in my case:
convert original_image.jpg -background transparent -fill grey -font Calibri -size 140x80 -pointsize 14 -gravity southeast -annotate +0+0 'copyright text' output.jpg