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On 2 Jul 2012, at 21:20, Stefan Stavrev stavrevste...@gmail.com wrote:
You mean it is complicated because conversion formulas are expensive, or lack
of agreement in the whole color spaces thing? I mean, there is a lot of
confusion about the color spaces, different
My recommendation for all of these ImageBugAlgo implementations
(contrast, histogram adjust, box filters, etc) is to completely ignore
color space.
I have reviewed the book referenced by Stefan, and I agree that it
makes a strong case that many image processing operations achieve
superior
Thanks for helping out Jeremy!
Just a small example to confirm I understand what you say:
Let's say that some algorithm needs hue and saturation. To achieve the
flexibility you talk about, I will need to keep anything color conversion
related outside of my functions. The documentation will say
Exactly!
So if your algorithm assumes an HSV like input, just note this super
explicitly in the documentation. (which channels each component is
in). And then leave it up to the user to perform the conversion.
Which algorithm, by the way, are you thinking of that requires hsv?
-- Jeremy
On
Jeremy, the box filter for color images I told you about needs hue and
saturation. I can't just apply the grayscale version of the box filter to
all channels independently, from what I have read it leads to bad results.
So I will have a general case where you can apply the grayscale box filter
to
Am I wrong to think that HSL (using some perceptual basis for getting luminance
from RGB) would be in all cases superior to ad-hoc HSV or HSI, which would not
have perceptually uniform brightness for all hues or saturations?
On Jul 3, 2012, at 11:44 AM, Stefan Stavrev wrote:
Jeremy, the box
I am working on histogram drawing.
What are all the possible ranges of values in one channel I should consider?
The usual ranges are 0-1 and 0-255. Any other ranges I should have in mind?
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On Wed, Jul 4, 2012 at 5:20 AM, Stefan Stavrev stavrevste...@gmail.com wrote:
I am working on histogram drawing.
What are all the possible ranges of values in one channel I should consider?
The usual ranges are 0-1 and 0-255.
Everything is converted to a float for our purposes, so these
Should granularity of bins also be a parameter? What is a sane
default for floats? Would it make sense to have such a parameter be
expressed in terms of size of the bin, or number of bins between the
high and low? Histograms are one area where I think things are
actually conceptually cleaner in
Hi Will,
You might have some ideas about this. For simplicity sake I made a decision
to draw the histogram in a fixed window 256x256. In Photoshop and After
Effects the histogram windows are of fixed size too. But in Matlab I
believe the image adjusts itself in size, it is not fixed. Usually the
How about width equal to the number of bins, height set by user?
I worry that fixing width at 256, it's going to be tricky or misleading to have
a different number of bins.
On Jul 3, 2012, at 3:45 PM, Stefan Stavrev wrote:
Hi Will,
You might have some ideas about this. For simplicity sake
On Jun 26, 2012, at 12:32 PM, Brent Davis wrote:
As an aside, what do you think about TiledIterator instead of
UnorderedIterator as a more descriptive name?
I think that TiledIterator could imply that Iterator doesn't use tiles,
even though it does (when using the cache, anyway). So I
On Jun 26, 2012, at 2:24 PM, Chris Foster wrote:
Side note: If we have TiledIterator, should we make it part of the
interface that Iterator visits pixels in scanline order? If not, there
doesn't seem much merit in even having a distinction.
It does beg the question about whether, if
I like the height set by user part, can be done easily. Will need to
specify min and max height though, for example 100 to 512. In Photoshop the
histogram has fixed height 100, smaller heights make no sense, since we
want the thing to be visible.
But not sure about having variable width. Since I
Requested feature from work. I think adding this lets somebody get rid of some
other tool.
IBA::render_text() is a very basic render text into the image pixels
functionality, exposed on the command line as oiiotool --text. You can fully
trick it out with optional arguments like:
oiiotool
I don't think you should have variable width. The only width that is easy to
do is when it's exactly equal to the number of bins you requested for the
histogram. Support that only, is fine with me.
-- lg
On Jul 3, 2012, at 8:21 PM, Stefan Stavrev wrote:
I like the height set by
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