Re: Comparing images [WAS: Re: Comparing pictures]

Understood.

I wasn't sure what you meant by "comparing". If they need to be identical it's not a problem but I thought it might mean finding the closest similarity.

For the latter I've used perceptual hashes (p-hashes) in the past with good results. They're also acceptably fast (I do ther comparison in images of several megapixels originally). They allow you to get a "score" of similarity and a confidence value, which helps taking decisions. The hash is text, so it's not memory intensive either.

Eduo

> On 19 Mar 2018, at 10:39, Jean-Luc Arnaud <jean-luc-E/[email protected]> wrote:
> 
>> you mean actually comparing the images themselves?
> Yes, indeed. But they are only icons, 32x32 or 16x16 pixels, so comparing pixel to pixel should be fast.
> 
> Jean-Luc Arnaud
> 
> Le 17/03/2018 à 12:39, Eduardo Gutierrez de O a écrit :
>> Hi, Jean-Luc
>> 
>> This is not what you're asking, but I'm intrigued.
>> 
>> When you say you're comparing pictures you mean actually comparing the images themselves? If so, are you using some sort of p-hash or the images are identical?
>> 
>> Eduo
>> 
>>> On 16 Mar 2018, at 17:42, Jean-Luc Arnaud <jean-luc-E/[email protected]> wrote:
>>> 
>>> Hi all,
>>> 
>>> I'm used to drawing icons in Listbox cells.
>>> 
>>> I need to compare these icons with pictures, in order to determine what action should fire when clicked.
>>> 
>>> I know coordinates of each icon in the cell.
>>> 
>>> 1) Is the RGBSurface and Pixel comparison a good way?
>>> 
>>> 2) How to get an RGBSurface of a cell area in the CellClick event? I can't figure out how to get a Graphics object of the area and then a RGBSurface.
>>> 
>>> All suggestion welcome, including MBS plugins use.
>>> 
>>> TIA for your help.
>>> 
>>> -- 
>>> Jean-Luc Arnaud
>>> 
>