Legacy ImageMagick Discussions Archive

I need to implement fast grayscale dilate / erode with flat circular structuring elements, and fast anti-aliased calculation of the signed Euclidean distance transform. ImageMagick has some useful stuff but it is too large of a library and too complicated to bring in just the parts that I need. My open source project is located here:

https://github.com/vinniefalco/LayerEffects

I'm trying to bring Photoshop Layer Styles to JUCE graphics drawing. Here's an example output:



and this is the C++ code:



So can someone help me or point me in the direction of anyone who might be interested in doing consulting work?

This is the right place.
I'll have a look when my stack is shorter. (2 months?)
At this point I have not idea whether I, or someone I work with, could help you.

If you're looking for speed, I'd have a look at VIPS code. Maybe you'll find something useful there? It has very fast erode/dilate code. For example, you may get somewhere by writing your disk as a sequence of 4 and 8 masks. (Again: I have no time now to check whether what you need, or something close, is in there. Also, libvips may be too "low level" for you.) http://github.com/jcupitt/libvips/tree.
Also have a look at OpenCV and PIL. (I assume you already poked around ImageMagick.)

I found it extremely difficult to integrate ImageMagick, OpenCV, VIPS into my project. They want to bring in a whole galaxy of types and functions, and if they are not present then nothing works. It's not clear how to take a piece of code and reuse it without taking the whole library with it.

thevinn wrote:I need to implement fast grayscale dilate / erode with flat circular structuring elements

In case no one knew, I have found that the Euclidean Distance Transform can be used to easily compute dilations and erosions with circular structuring elements.

Question: What is the largest diameter of your disks (in pixels)?

NicolasRobidoux wrote:Question: What is the largest diameter of your disks (in pixels)?

Well I'm trying to replicate all of the Photoshop Layer Styles, so 250.

But like I said, erosion and dilation can be expressed in terms of the distance transform, which I have finally got working.

I know for programmers you can go to elance or odesk and find someone there or you can even go to craigslist and find someone to do it cheap.

GooseTracks wrote:I know for programmers you can go to elance or odesk and find someone there or you can even go to craigslist and find someone to do it cheap.

In my experience, elance / odesk / craigslist type places are worse than useless for finding specialized programmers in these types of fields.