I need to resize image based on memory.
What I am getting is following option in "convert" command.
-resize 800x600
-resize 25%
Is there any command like -
-resize 10KB
Thanks
Use this:
convert input.jpg -define jpeg:extent=300kb ... output.jpg
If you want a way to do something similar with Python, I wrote an answer that works pretty well here. It does a binary search for a JPEG quality that satisfies a maximum size requirement.
Related
I've got an 540x540 image of 54x54 color squares (same sizes).
When I resize it to 54x54px it looks horrible (blurred), shouldn't a resize like this be perfectly done with imagemagick?
is I possible to get it perfect?
I've tested convert source.png -resize destination.png and -adaptive-resize but the result is the same..
I see what your confusion is now... the problem is not that the process is lossy, rather it is because the -resize is doing more sophisticated processing than you want in order to make an attractive job that you would want for, say, photographs. You want a very simple point sampling process which will produce simple blocks of pure, uncombined colour.
I'll make a start image:
magick -size 10x10 xc:red +noise random -scale 540x540 start.png
And scale it down, by taking a point sample in each block:
magick start.png -sample 10x10 small.png
And back up:
magick result.png -scale 540x540 reincarnated.png
I'm resizing my image using imagemagick, however, I'm not specifying the exact size:
convert $filename -resize 1080000# -quality 100 $reduced_filename
it's resized within a bound, now the problem is, after resize, the size in the EXIF is no longer correct, and I don't have a clue of calculating the new size (e.g. percentage resize can let me calculate new size based on percentage).
So is there a way to get image size after resizing?
Thanks!
You can use ImageMagick's "convert" command to access the image dimensions with a command like this...
convert $filename -format "%[w]x%[h]" info:
Like this...
First create a start image 1024x768:
convert -size 1024x768 xc:black start.jpg
Now resize, and output new size info in one fell swoop:
convert start.jpg -resize 50% -format "%wx%h" -write info: result.jpg
512x384
I've read the ImageMagick documentation here and here and been unable to achieve a couple of simple tasks. Would appreciate any simple pointers or direction, or even commands I can execute that will work on Linux.
I want to convert any image-type (JPG, GIF, PNG, TIFF) to save to a PNG, losslessly, and as compressed as possible without any loss of quality. Ideally in 96 DPI so they look good in Retina screens.
To then take the above generated PNG and also resize it in specific sizes, with height and width specified.
What am I missing with the convert command?
If you want to convert a TIF, GIF or JPEG to PNG, the command is:
convert image.tif result.png
or
convert image.jpg result.png
In answer to your questions...
Question 1
PNG is lossless by definition, so that is not an issue. To get better compression of a PNG, you generally need to reduce the colours, i.e.
convert image.jpg -colors 64 result.png # or try 255 which allows a palettised image
The dpi is pretty irrelevant until you print on paper. More pixels are needed if you want more quality on screen.
Question 2
If you want to resize an image without destroying its aspect ratio, use
convert image.jpg -resize 200x100 result.png # retain aspect ratio
If you don't care if that makes the image look stretched or distorted, and you want exactly 200x100, tell ImageMagick that you really mean it by shouting:
convert image.jpg -resize 200x100! result.png # ignore aspect ratio
I converted a 2.9M jpg to a 20x20 using 8 as the quality. but that file's size is still 48k.
here is my command
convert 238832c58dc3bc0b_29M.jpg -quality 8 -resize '20x20>' +repage 238832c58dc3bc0b_20x20.jpg
and after conveted, 238832c58dc3bc0b_20x20.jpg is 48k. I tried smalled size and quality, still 48k. it shouldn't be so big. it should be less than 10k. anybody know how to enhance it? thanks
Use -thumbnail instead of -resize or add -strip to your command.
Thumbnail removes the EXIF information apart from the color profile and strip removes the color profile as well.
I want to pixelate and/or blur an image.
I've found the command for the blurring:
$convert image.jpg -blur 18,5 newimage.jpg
to work but I cannot blur the image any more.
And how do I pixelate the image? I couldn't find a sound example around the net.
Thx
To get a proper square pixellation, try:
convert -scale 10% -scale 1000% original.jpg pixelated.jpg
This worked nicely for me, gives a sort of cross between pixelating and blurring:
convert -resize 10% image.jpg newimage.jpg
convert -resize 1000% newimage.jpg newimage.jpg
You can be sure that the data cannot be retrieved, should that be important to you.
Changing the %ages will change the amount of pixelation/blur
I don't know anything about ImageMagick, but you can try resizing the image using bicubic to a much smaller dimension, then resizing the image back to a bigger one.
The trick works using .net's System.Drawing object.