The ImageRead function performs the same operation as the cfimage read action . However, you cannot use the cfimage tag to read and create. You can use the cfimage tag to perform common image manipulation operations as a border; captcha; convert; info; read; resize; rotate; write; writeToBrowser. The other day, I needed to do some on-the-fly conversion of PNG image files to JPG format in ColdFusion. This was part of stop-gap measure at.
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Convert an image from one file format to another.
Converting an image to grayscale using the CFIMAGE tag in ColdFusion
Due to the wide array of image functionality in ColdFusion 8, I am going to try and break this tutorial up into several small and manageable parts.
If specified, the value must be an integer. ColdFusion’s cfimabe image functionality is just plain awesome. You can manipulate ColdFusion images in memory and write them to a file, a database, or directly to a browser.
This gives us the same output, but the source attribute is “http: For more information about what these do as they are undocumentedtry exploring the java. Therefore, if you are in an included template, you might get files stored in unexpected places if you don’t fully grasp this concept.
Valid values are fractions that range from 0 through 1 the lower the number, the lower the quality. The other input types give a similar output, so I won’t show the CFDump, however, I will walk through the code. You can use the write action to change the quality of a JPEG image to reduce file size.
So I am forced to make it a bit bigger to get rid of that white border. Reading an image from a URL and writing it to disk covnert be done this way: The convert and write actions require a destination. The next input type is a Base64 encoded string. Now, when I first saw this action, Convet had assumed it was working the same way CFContent worked – by streaming the file to the browser as the only returned content.
Enter a six-digit value, which specifies the RGB value.
The ColdFusion image on which this operation is performed. I don’t generally deal with these sorts of objects:. The next input type is a URL sha-wing! Values between 00 and FF are allowed. ColdFusion calculates the width proportionally to the height. The following example shows how to reduce the size of an image and display it in the browser: Graphics2D getCurrentImage – returns: You can specify a specific interpolation algorithm by name for example, hammingby image quality for example, mediumQualityor by performance for example, highestPerformance.
Image crop float, float, float, float – returns: The following are cfimwge valid cfimagge. Also, image quality can degrade; for example, PNG images support bit color, but GIF images support only colors. The absolute or relative path name to which you are going to write the image. To specify the height or width in pixels, enter the integer, for example, Now that we have covered the tag-based reading, let’s examine reading in images using the new ColdFusion 8 image functions.
If the destination file already exists, ColdFusion generates an error if the overwrite option is not set to yes.
ColdFusion Help | cfimage
Generates HTML to output the image in place. The next one on the list is the Web-relative path: You can use the cfimage tag to perform common image manipulation convvert as a shortcut to Image functions. You cannot display a GIF image in a browser.
The following table describes the algorithms and their named equivalents based on average test results: The border is added to the outside edge of the source image, increasing the image area accordingly. Height in pixels of the image. The com image format is not supported on this operating system. I don’t want to start writing a lot of images to the browser only to find out that it is clogging up this temp directory.
ColdFusion Help | ImageRead
If you look at the source of the page with the rendered inline image, you will see something like this:. We don’t have to perform actions just on new images; we can cfimmage them on existing image objects: Converting transparent images images with alpha can degrade image quality.
For example, using a URL with this query string: To start with, let’s look at ImageRead.