imagemagick

Python OSError not reporting errors

Ive got this snippet that Im using to convert image files to tiff. I want to be informed when a file fails to convert. Imagemagick exits 0 when successfully run, so I figured the following snippet would report the issue. However no errors are being reported at all. def image(filePath,dirPath,fileUUID,shortFile): try: os.sy...

Light effect with image magick

Hello, I'm using ImageMagick to resize an image to a smaller size gif. In this process I'm trying to give the image a light effect, not a side-light, just like a shiny look all over. Not a good comparison but for a better understanding think of an image seen in a old screen or an image seen in glossy monitor - I'm trying to enhance the ...

In a digital photo, how can I detect if a mountain is obscured by clouds?

The problem I have a collection of digital photos of a mountain in Japan. However the mountain is often obscured by clouds or fog. What techniques can I use to detect that the mountain is visible in the image? I am currently using Perl with the Imager module, but open to alternatives. All the images are taken from the exact same posit...

RMagick returns nil reading JPEG

When I try to open a JPEG format file in Rails using RMagick, it always return nil with any jpg file. Other file formats open well. $ script/console Loading development environment (Rails 2.3.4) >> require 'RMagick' >> img = Image.read("1.gif").first => 1.gif GIF 230x100 230x100+0+0 PseudoClass 256c 8-bit 2kb >> img = Image.read("1.png"...

JPG File Size Optimization - PHP, ImageMagick, & Google's Page Speed

I have photo gallery code that does image re-sizing and thumbnail creation. I use ImageMagick to do this. I ran a gallery page through Google's Page Speed tool and it revealed that the re-sized images and thumbnails both have about an extra 10KB of data (JPEG files specifically). What can I add to my scripts to optimize the file size?...

Fastest way to compute a "Visual" checksum of an image

I'm looking to create an ID system for cataloging images. I can't use md5() since that will change if I alter the EXIF tags of the image. I am currently using the SHA1 checksum computed by imagemagick. It works perfectly, but it's really, really slow on larger images (~15 seconds on a quad-core xeon for a 21 megapixel JPG). Are t...

Imagemagick PDF to JPG conversion failing

I'm trying to convert the first page of a PDF to a JPG. I'm pretty sure I got this to work with certain PDFs, but is it really possible that certain PDFs are made incorrectly and cannot be converted? I tried running this first: $ convert 10-03-26.pdf[1] test.jpg And I got the follow: Error: /syntaxerror in readxref Operand stack: E...

Resizing screenshots/screen captures for inclusion in Beamer

Sorry, this may or may not be a programming question directly, but I am trying to resize screenshots with Imagemagick and Gimp to include in a Beamer presentation, but it comes out even blurrier than the resizing done by LaTeX. For instance, in Beamer I might have a command to rescale the image \includegraphics[width=.5\textwidth]{fig....

Prevent image cropping when making sprites from gif

Hey guys I've tried several tools (imagemagic, gif2png, Nconverter) to extract frames to make sprites from a .gif image that i have. I get the .pngs just fine, but they'r not the same size, some are 50x65 some 43x65 some 50x70, Which really screws any attempts at a descent animation. So is there a way to prevent this cropping or program...

Get used color names from image

Hello, I would like to check what colors is present in a image. This will be stored in the database and used for a search form. (red=1, green=1, blue=0, yellow=1, black=1, white=1 etc.) img = Magick::Image.read('phosto-file.jpg').first img = img.quantize(10 h = img.color_histogram pp h {red=12815, green=18494, blue=15439, opacity=0=>13...

Detect Alpha Channel with ImageMagick

Scenario I would like to save images with alpha transparency as .png and images without alpha transparency as .jpg (even if their original format is .png or .gif). How can I detect whether or not an image has alpha transparency using ImageMagick? ...

How to execute Imagemagick in PHP

I found a very helpful post on here about cropping images in a circle. However, when I try to execute the imagemagick script using exec in PHP, I'm getting no results. I've checked to make sure the directories have the correct permissions and such. Is there a step I'm missing? Any insight would be much appreciated. Here's what my script...

Imagemagik Change an images dpi from 400 to 72

I have an image on my server which I know the dpi of and if it's too high I want to size it down to 72 I still want to keep the same height and width of the image. Any ideas? I've played around with -resample -units and -density but don't seem to be getting anywhere and can't find any answers. Anyone out there that can help ...

imagick showing script url instead of image

Hi, currently i'm trying to use imagick to generate some images without saving them on the server and then outputting to the browser, my method of choice was image magic with the imagick extension for php. I read the documentation, and i'm sure the package is installed on my machine (windows xp, with xampp). the class is installed imag...

Pipe dynamic PDF into Imagemagick and convert to PNG

I need to create thumbnails from dynamic (database driven) pdf's. I've used a variation of the script below in the past, but this doesn't seem to be working for me now (page just hangs). <?php require_once('./template/all_includes.php'); $descriptorspec = array( 0 => array("pipe", "r"), // stdin is a pipe that the child will read...

Imagemagick - File Naming

I am using the convert command to convert a pdf to multiple pngs, I need the naming conventions to be slide-##.png at the moment they come out like slide-1.png but because there is 20+ slides when I loop through them to add them into the model the order comes up wrong, so it looks like slide-1.png slide-10.png slide-11.png and so on, how...

Choosing suitable background / foreground colour using PHP

I am looking to find a why to calculate a suitable background colour and a colour for the text that would go over the top, obviously I need to take into account readability and accessibility. I would need to pick the two colours from the array, the colours are stored in their hex representations. #CC9966 #996633 #FFCC99 #CCCC99 #000000...

ImageMagick vs. Cairo on Vector Graphics rasterization

I am working on a project that needs rasterizing of drawings into image files. I have already got it work using GDI+. Wanting to create a portable solution, I am also looking into other solutions and found two - cairo and imagemagick. I am new to both, but it seems that ImageMagick can do almost all the stuff - drawing lines, arcs, circl...

Make ImageMagick recognize a font

I've been playing image generation on ImageMagick on Ubuntu 9.10. I want to be able to get it to recognize a font so that I may call it by it's "nickname". I can find the list of fonts ImageMagick recognizes by typing identify -list font In that list I see Times-Bold. Therefore convert -font Times-Bold label:abcdef times.gif will ge...

How to remove EXIF data without recompressing the JPEG?

I want to remove the EXIF information (including thumbnail, metadata, camera info... everything!) from JPEG files, but I don't want to recompress it, as recompressing the JPEG will degrade the quality, as well as usually increasing the file size. I'm looking for a Unix/Linux solution, even better if using the command-line. If possible, ...