Re: Image Thresholding for Binary workflow

Posted by Rainer M. Engel on
URL: http://imagej.273.s1.nabble.com/Image-Thresholding-for-Binary-workflow-tp5007850p5007870.html

Hello John,

that is definitely worth a look. Maybe also the already available "Image
Expression Parser"?, although then I would like to know how does the
Macro Expression work? Isn't it build upon the ByteProcessor function
and hence it won't get faster?

Rainer


Am 22.05.2014 12:08, schrieb John Hayes:

> Hi Rainer,
>
> Check out the ByteProcessor::threshold function:
>           Sets pixels less than or equal to level to 0 and all other pixels to 255.
>
> HTH and best regards,
>
> John
>
> Le 22 mai 2014 à 11:23, Rainer M. Engel a écrit :
>
>> Hello together,
>>
>> I'm looking for way to threshold an image and in the same process making
>> it binary.
>>
>> Process > Binary > Make Binary
>> sometimes caused plausible black/white dominance switches.
>>
>> Process > Math > Macro
>> works better for my purposes (i.e.| if (v<=25) v=0; else v=255)
>>
>> The later Expression is very slow compared even to an Gaussian Blur or
>> similar. Are there other, hopefully faster ways (for high resolution) to
>> threshold and make binary (8bit)?
>>
>> I tried ..
>> setMinAndMax(173, 173);
>> .. but this does no clamping like I thought it might..
>>
>> Any help is much appreciated.
>>
>> Best regards,
>> Rainer
>>
>>
>> --
>> Rainer M. Engel, Dipl. Digital Artist
>> scientific|Media GbR
>> Pichelsdorfer Str. 143
>> 13595 Berlin
>>
>> --
>> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>
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