ImageMagick

问题 I am trying to convert an sRGB bitmap file to greyscale using ImageMagick. I've tried using convert -set colorspace Gray and convert colorspace Gray , which according to the documentation should do it. However, when I try to check the output file using identify -format "%[colorspace]" <outputfile> it still tells me that it is in sRGB. I am aware that not all file formats support all colourspaces, and tried converting the bitmap to a png first, then changing the colorspace and converting it

问题 How to extract metadata from a image like this website? I have used exev2 library but it gives only limited data as compared to this website. Is there some more advanced library? I have already tried hacoir-metadata Python library. Also how does Windows extract details of image (the one we see from properties)? 回答1: PNG files are made up of blocks, most of which are IDAT blocks which contain compressed pixel data in an average PNG. All PNG's start with a IHDR block and end with an IEND block.

问题 How to extract metadata from a image like this website? I have used exev2 library but it gives only limited data as compared to this website. Is there some more advanced library? I have already tried hacoir-metadata Python library. Also how does Windows extract details of image (the one we see from properties)? 回答1: PNG files are made up of blocks, most of which are IDAT blocks which contain compressed pixel data in an average PNG. All PNG's start with a IHDR block and end with an IEND block.

问题 I’m looking for alternatives for line scan cameras to be used in sports timing, or rather in the part where placing needs to be figured out. I found that common industrial cameras can readily match the speed of commercial camera solutions at >1000 frames per second. For my needs, usually the timing accuracy is not important, but the relative placing of athletes. I figured I could use one of the cheapest Basler, IDS or any other area scan industrial cameras for this purpose. Of course there

问题 I have get the image pixel of an image at the particular point using getImagePixelColor. $pixel = $image -> getImagePixelColor($x,$y); Now I have modified that pixel's color using some method and now I want to set the new color of that pixel. How can I do ? There is a setColor function. But I got the pixel from the Imagick class. But the setColor function is in the ImagickPixel class. So how can I do it ? 回答1: ->getImagePixelColor() returns an ImagickPixel object anyways, so $pixel->setColor(

问题 I am trying to resize an image (using imagemagick) to keep it's current aspect ratio but fit it into a 4/3 container. This is the command I have so far: magick convert ./horse.jpeg -background white -gravity center -extent 4/3 ./hourse_output.jpeg This is what I'd like: . As you can see, the image is "put into" a 4/3 container. 回答1: My error. The aspect ratios such as 4:3 in ImageMagick -extent will only crop and not pad. See my bash unix script "aspectpad" at http://www.fmwconcepts.com

问题 For example, I have two files: aaa.jpg (with cat) aaa.png (with dog) As you can see, images are different, despite of their names, which are the same. I want to convert both these images to one single format. The basic attempt for this task is mogrify -format jpg *.png But it doesn't work, for obvious reasons (one folder cannot contain multiple files with the same name and extension). Also, some notes from myself. Please note, this is just example. In real life, it would be about 100-200

问题 I'm building a Node.js application to convert PDF to PNGs and display on the user page. The app will work like this: User uploads a PDF to the server Server converts the PDFs pages to individual PNGs Display PNGs on the User page I found a great package called Node ImageMagick https://github.com/rsms/node-imagemagick but Its not a perfect fit. Some things like -monitor flag from ImageMagick doesn't work but doesn't work on vanilla node.js as well: var exec = require('child_process').exec;

问题 Command: convert | head -n 4 Shows this Version: ImageMagick 6.7.8-9 2014-05-12 Q16 http://www.imagemagick.org Copyright: Copyright (C) 1999-2012 ImageMagick Studio LLC Features: OpenMP Then when i run this: <?php $imagick = new Imagick(); $imagick->readImage('test.pdf'); $imagick->writeImages('image.jpg', false); echo 'Aw'; ?> Shows this error: PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib64/php/5.6/modules/imagick.so' - /usr/lib64/php/5.6/modules/imagick.so: cannot open

问题 I Installed ImageMagick (ImageMagick-6.9.2-3-Q16-x64-static.exe) and add in my js file following: var easyimg = require('easyimage'); but when I start my node.js app I get this error: ImageMagick Not Found EasyImage requires ImageMagick to work. Install it from http://www.imagemagick.org/script/binary-releases.php. 回答1: Make sure the ImageMagick directory is in your path. Add it to your system or user PATH environment variable. Test by opening a new command window and running the following: