I have a number of PNG image files that I'd like to increase in size. I do not want to rescale the image. I just want to extend the white background further down and to the right. In GIMP terms what I want is to increase the Canvas Size, and cover the increased area with white pixels, in a batch context. The input images may be different sizes, but the output images should all be a fixed size (e.g.: 1280 x 720 pixels).
I've tried this with various online tools, with GIMP, and with a very old version of Photoshop. Most of the tools I've tried to date do one of the following which I don't want:
Rescale the existing image to cover the new canvas size, or
Center the starting image and extend the canvas in all directions, or
Fail to perform this in a batch mode.
I just want to extend existing PNG images with additional white pixels down and to the right. What's the easiest way to do this to a large number of files?
imagemagick is a common tool for this. the -crop operation combined with -gravity can probably do what you want.
magick input.jpg -crop 1000x1000+0+0\! -background white -flatten output.png
source for the magick spell: https://legacy.imagemagick.org/Usage/crop/
In ImageMagick, you process a whole folder of images using mogrify. You can extend them using -extent. With mogrify, it is wise to first create a new empty directory to hold the results. So
cd image_directory
mogrify -format png -path path/to/new_directory -background white -gravity northwest -extent WxH *.png
Where WxH, is your desired final width and height after padding with the white. This assumes that all images will be padded to the same width and height
Expand By Size
cd test1
mogrify -format png -path ../test2 -background white -gravity northwest -extent 500x500 *.jpg
Expand By Percent
cd test1
mogrify -format png -path ../test2 -background white -gravity northwest -extent 150x150% *.jpg
For ImageMagick 7, add magick before mogrify. So "magick mogrify ..."
The ImageMagick command that did what I needed used "convert" with the -geometry and -composite arguments. In a Windows batch file context:
for %%a in (img*.png) do (
magick convert -size 1280x720 xc:white "%%a" -geometry 512x384+40+40 -composite "work-%%~na.pdf"
)
Related
I have two images:
a.jpg
b.jpg
Both images are square (100x100 pixel). I want to cut a circle with a radius of 50 from image a.jpg and paste it in the middle of image b.jpg. I want to save the result in c.jpg.
How can I do this with Linux command line tools? I need to do it within a shell script.
Many different techniques can be used. ImageMagick has FX language that can perform complex calculations.
convert a.jpg b.jpg -fx 'Wi=w/2; Hi=h/2; hypot(Wi-i, Hi-j) < 50 ? u : v' c.jpg
For example...
convert -size 100x100 PLASMA: a.jpg
convert -size 100x100 GRADIENT:LIME-ORANGE b.jpg
convert a.jpg b.jpg -fx 'hypot(50-i, 50-j) < 50 ? u : v' c.jpg
Update with another technique.
A faster approach can be leveraging image mask(s) of the shape you wish to crop, and compose/composite it between both images. It'll require a format that supports alpha channels, but only for the initial work. For example...
Create a circle mask, and copy values to alpha channel.
convert -size 100x100 xc:White -fill Black \
-draw 'circle 50 50 50 5' -alpha Copy mask.png
convert \( a.png mask.png -alpha Set -compose Dst_Out -composite \) \
b.png -compose Dst_Atop -composite c.png
Eric's approach is much more succinct, and probably preferable, but here is another way anyway. I am being very environmentally aware and recycling ;-) his start images:
magick b.jpg \( a.jpg \( +clone -threshold 101% -fill white -draw "circle 49,49, 49,99" \) -channel-fx '| gray=>alpha' \) -flatten result.png
That says... "Load b.jpg as the background. Load a.jpg and then create a transparency mask by cloning the entire a.jpg setting it black and drawing a white circle in it and pushing it into the alpha channel. Then flatten that over the top of b.jpg".
The result is the same as Eric's.
I need to count pixels in an image that are not background color.
I am calling this from PHP (it's from ImageMagick):
gm convert test.png -fill black +opaque "rgb(255,255,255)" -fill white -opaque "rgb(255,255,255)" -print "pixels = %[fx:w*h*mean]\n"
But it does not give any result, nothing.
I tried using histogram instead:
gm convert test.png -define histogram:unique-colors=true -format %c histogram:info.txt
That works, but gives values for every color and more details, I just need a single number please.
You have got a couple of issues here. You seem to be trying to mix GraphicsMagick with ImageMagick when they are not the same thing.
Firstly, GraphicsMagick does not have the +opaque operator that ImageMagick has.
Secondly, it doesn't have the -fx operator that ImageMagick has for doing maths.
I would suggest you move to, the more powerful, ImageMagick. Then it will work as you expect:
# Create a test image
convert -size 200x200 xc:black xc:white xc:red +append image.png
# Count the white pixels
convert image.png -fill black +opaque "rgb(255,255,255)" -print "pixels = %[fx:w*h*mean]\n" nul:
pixels = 40000
If you really, really must do it with GraphicsMagick, I can only suggest the following - which is heavily based on #GlennRanders-Pehrson answer here:
gm convert image.png +matte -matte -transparent white -operator matte negate 1 result.png
gm identify -verbose result.png | grep -EA5 "Opacity:|Geometry:" | grep -E "Mean|Geometry"
Geometry: 600x200
Mean: 43690.00 (0.6667)
Mean: 43690.00 (0.6667)
And your answer will be:
600 * 200 * (1 - 0.667)
I have an image with around 20% of its bottom filled with white color. But the image has some dots of other colors than white. I have 100s of such images which I would like to remove those dots from.
I have been using ImageMagick commands, and bash scripts to automate several tasks but I cannot find any command to fill certain percentage of an image from bottom by a solid color.
The dots are marked by arrow in the screenshot. A sample command or a hint would be great!
I achieved the goal by calculating the height, taking percentage (approximate) of the image's height and filling a white rectangle.
# A tool to fill up 10% of the bottom of given image
# by white color. Useful to remove unnecessary colors
# at the bottom of image.
# Usage: this_script.sh required_image.jpg
#!/bin/bash
image=$1
right=`identify -format %w $image`;
bottom=`identify -format %h $image`;
top=`expr $bottom \* 9 / 10 | bc`;
left=0
convert $image -fill white -draw "rectangle ${left},${top},${right},${bottom}" $image
This can be automated for several images in a folder like:
for img in *.jpg; do bash <script>.sh $img; done
You can do this in a single step like this:
convert in.png \
\( +clone -gravity south -crop x10% -evaluate set 100% \) \
-composite out.png
Essentially, we read in the image and then do some "aside processing" - a delightful term coined by ImageMagick guru Kurt Pfeifle. The "aside processing" starts with (\ and ends with \). In there, we clone the image (i.e. create a copy of it) and chop off the bottom 10%, which we then fill with white. At the end of the "aside processing", this white image is still in our image stack so we tell ImageMagick to composite that on top of the original.
Result:
I'm working on a little script that generates a sprite sheet. I have 6 spritesheets and I need to re-organize them and put their content (once ordered) in a unique file.
I logically chose to use ImageMagick. But here I'm stuck.
Here is what I have so far :
convert '%d.png[0-5]' \( -crop 456x912+0+0 -crop 3x6+0+0# +append \) -append test.png
This command line takes my 6 files (0.png to 5.png) crop them, and split them into 18 sprites. Once splited, the 18 sprites are aligned horizontally and then aligned vertically with the 18 previous one.
The problem is this command seems to only aligned them horizontally. Instead of being composed of 18x6 sprites, test.png is composed by 108x1 sprites.
Any idea how to perform this in one command ?
You might try another imagemagick tool, "montage," for this one.
$ for i in `seq 1 18 `; do convert -background none -fill black -size 32x32 -pointsize 14 caption:"$i" $i.png; done
$ montage `ls ?.png` `ls ??.png` -tile 6x3 -geometry 32x32 tile.jpg
How do I tile an image using ImageMagick? I don't think I can use montage because I want the columns displaced by 50% of the original image height.
It's probably easier to show an example of what I'm trying to do:
Start with:
End with:
Thanks!
In case you want plain tiles, without shifting down the second column and the rest of the even columns, you can use this script:
convert -size 800x600 tile:Ball.jpg Tiles.jpg
(probably the majority of people landing on this question want such plain tiles, like I did)
My "Ball.jpg" is 200 x 200 pixels, so this script creates a 4x3 tile image.
For ImageMagick 7 users, replace convert with magick.
Thanks to Fred at Fred's ImageMagick Scripts, here's the solution:
infile="tile.png"
h2=`convert $infile -format "%[fx:round(h/2)]" info:`
convert $infile \( -clone 0 -roll +0+$h2 \) +append -write mpr:sometile +delete -size 1000x500 tile:mpr:sometile output.png
This is exactly what I was looking for.
Even though you did not mention anything about context of usage, I will put it here so more people are aware. Fred's scripts are for non-commercial use. I ended with an alternative solution, however, principle is the same:
Creating shifted tile by:
convert _orange_270.jpg -roll +0+135 _orange_270_r.jpg
Create a column of regular tiles:
montage _orange_270.jpg +clone +clone +clone -tile x4 -geometry +0+0 _1col.jpg
Create a column of shifted tiles:
montage _orange_270_r.jpg +clone +clone +clone -tile x4 -geometry +0+0 _2col.jpg
Combined regular and shifted columns:
montage -geometry +0+0 _1col.jpg _2col.jpg _2cols.jpg
Created full tiled image using last output from point 4:
convert _2cols.jpg -write mpr:tile +delete -size 1920x1080 tile:mpr:tile _wallpap.jpg
Result:
If on a unix-like system with ImageMagick, you could just use my script, tileimage at http://www.fmwconcepts.com/imagemagick/tileimage/index.php.
It provides numerous variations on the flipping, rotation and offsets.
If non-commercial use, then it is free, If commercial use, then contact me for a license.
Information about tiling in ImageMagick can found at http://www.imagemagick.org/Usage/canvas/#tile