I'm trying to write a command in sh using the software ImageMagick. I was trying to find a command that allows me use any image( presumably jpeg) and be able to preview the image but at a 200x200 pixels instead of the original size?
display -size 200x200 filename
See http://www.imagemagick.org/www/display.html
I use xv or xview:
xv -geom 200x200 filename
xview -geometry 200x200 filename
Related
I've got a 16x512 image comprised of 16x16 images. I want to seperate them, individually scale each one down to 16x8, then put them all back into their full 16x512. I've got a basic idea, but I'm having trouble executing it.
Using the commands from unix stackexchange, I split by file by using convert -crop 16x16 my_image.png crop-%d.png, which yields 32 images (512 / 16 == 32). My next step was where trouble has started. From askubuntu, I found the command mogrify -resize 16x8 crop-*.png, however this does not yield 16x8 images, but rather 8x8, which I do not want. Furthermore, this post on stackoverflow gives me the command for merging these images, which is convert crop-*.png -append my_image_cropped.png, however it does not yield a 16x512 like I want, but rather 8x256 (the 8 is due to the previous bug, but I still want a height of 512, not 256).
What do I need to accomplish my goals? The image in question can be found on imgur.
Edit: Here are some images which will describe the basic idea
The full image:
Both 16x16 and 16x8 side by side
The finalized image, basically the 16x8 will sit in the 16x16 area (right at the bottom part, that is essential), but won't fully fill it.
I am not sure I understand what you want to do. But if you resize 16x8, Imagemagick will keep aspect ratio. If you want to force it to be exactly 16x8 and can accept distortion, then use the ! flag. But you then say you want to put the 32 pieces back to form 16x512, but the resize will make it 16x256, since you have 32 image of height 8. So you have to resize again. Here is how to do that, if that is really what you want.
Create a gradient image for testing:
convert -size 16x512 gradient: grad.png
Do the processing:
convert grad.png -crop 16x16 -resize 16x8! -append -resize 16x512! newgrad.png
Note that proper Imagemagick syntax reads the input first.
ADDITION:
Given your new information in your comment, try this:
convert grad.png -crop 16x16 -resize 16x8 -gravity northwest -background none -extent 16x16 -append newgrad.png
Change the background color as desired and the gravity setting as desired for positioning.
I want to resize image to an exact size by maintaining aspect ratio and filling the empty space with transparency using nodejs.
I am able to do it using canvas. But due to some server os issues I can not use canvas.
I tried with imageMagick and gm. But couldn't find any option like these. Please show me a way to do this.
Thanks in advance.
In ImageMagick, you can resize and fill to the exact size by
convert image -resize WxH -background none -gravity center -extent WxH output
Input:
Here I will make the background black so you can see that if fills it out.
convert lena.jpg -resize 400x300 -background black -gravity center -extent 400x300 lena1.jpg
In case you have been successful using the canvas for resizing images, you can check out https://github.com/Automattic/node-canvas this repo.
As already mentioned you also resize images using ImageMagick by processes in NodeJS ( http://www.imagemagick.org/Usage/resize/ )
convert dragon.gif -resize 64x64 resize_dragon.gif
In case you have a lot of images, I would suggest that you write a terminal script ( NodeJS can achieve that as well ).
I hope it helps, in case you have more queries, feel free to ask.
I am using GraphicsMagick and I am trying to create a 200px by 200px transparent TIF image. However, the resulting image, when opened in Photoshop, has a black background. If I use ImageMagick, it works.
The following ImageMagick command creates a transparent image (when opened in Photoshop)
magick convert -size 200x200 xc:transparent transparent1.tif
But, the same GraphicsMagic command creates a black image (when opened in Photoshop)
gm convert -size 200x200 xc:transparent transparent2.tif
I am at a loss. I would like to use GraphicsMagic because the Node API has streaming support and provides some other nice features.
I'm converting pdf files to images with ImageMagic, everything is ok until I use -resize option, then I get image with black background. I use this command:
convert -density 400 image.pdf -resize 25% image.png
I need to use -resize option otherwise I get really large image. Is there any other option which I can use to resize image or is there option to set background in white.
That's not a Ghostscript command, You will need to find out what convert is sending to Ghostscript. As it stands I can't even be sure that your problem is with Ghostscript ,since it could easily be something that convert is doing.
Solved it by removing alpha from image, it seems imagemagic tries to apply some opacity but since jpeg doesn't allow transperency result was black background. So I found example on imagemagic website and it helped me:
convert a.pdf -background skyblue -alpha remove -alpha off a_remove.jpg
I want to use CSS sprites on a web site instead of separate image files, for a large collection of small icons that are all the same size. How can I concatenate (tile) them into one big image using ImageMagick?
convert works much better than montage. It arranges images vertically or horizontally and keeps png transparency.
convert *.png -append sprites.png (append vertically)
convert *.png +append sprites.png (append horizontally)
From the page you linked, 'montage' is the tool you want. It'll take a bunch of images and concatenate/tile them into a single output. Here's an example image I've made before using the tool:
(source: davr.org)
You are looking for:
montage -background transparent -geometry +4+4 *.png sprite.gif
I like this script for automatical sprite/css generation.
"Building CSS sprites with Bash & Imagemagick"
article copy in Waybackmashine https://web.archive.org/web/20150529041037/http://jaymz.eu/blog/2010/05/building-css-sprites-with-bash-imagemagick
script copy http://blog.kupriyanov.com/2011/01/solvedbuilding-css-sprites-with-bash.html