Search found 50 matches

by TedBaker
2017-11-13T13:38:27-07:00
Forum: Users
Topic: input Linear RGB specifiy output RGB or sRGB
Replies: 36
Views: 14424

Re: input Linear RGB specifiy output RGB or sRGB

but which one has the bug? ... I suggest you reduce the commands to the minimum that shows the difference between versions. For example, I suspect the lines with "-poly" have no significance. When you have "-channel" in a command, you should always have a "+channel" after the operations you want re...
by TedBaker
2017-11-13T12:52:18-07:00
Forum: Users
Topic: input Linear RGB specifiy output RGB or sRGB
Replies: 36
Views: 14424

Re: input Linear RGB specifiy output RGB or sRGB

Start simple. Then when you understand that, then add your other clone processing. Which is how I discovered the bug. Tiff does not support RGB colorspace nor gamma=1 My point exactly, pick any tiff file you like, and then process it, with 6.9.7-4, 6.9.9-20 or 6.9.9-23, you would expect the same re...
by TedBaker
2017-11-13T08:29:06-07:00
Forum: Users
Topic: input Linear RGB specifiy output RGB or sRGB
Replies: 36
Views: 14424

Re: input Linear RGB specifiy output RGB or sRGB

Just following up, as there is indeed a bug somewhere. 6.9.7-4 gives a different result than 6.9.9-20, 6.9.9-24 with the use of: convert logo.tif -strip -set colorspace RGB \ -fx "u?u:1" \ -separate \ \( -clone 0 -poly ".1,-1" -poly "1,1.65" \) -swap 0,3 -delete 3 \ \( -clone 1 -poly ".1,-1" -poly "...
by TedBaker
2017-11-13T06:02:30-07:00
Forum: Users
Topic: input Linear RGB specifiy output RGB or sRGB
Replies: 36
Views: 14424

Re: input Linear RGB specifiy output RGB or sRGB

Thanks fred, but I don't think my post got the point across, and I am still confused what the rules are, or in fact if there is a bug somewhere... 6.9.7-4 The first part of my example probably caused confusion, so lets start with a tif file which I want to consider as linear. My understanding is the...
by TedBaker
2017-11-12T20:49:23-07:00
Forum: Users
Topic: input Linear RGB specifiy output RGB or sRGB
Replies: 36
Views: 14424

Re: input Linear RGB specifiy output RGB or sRGB

In my case my input file is linear, and I want to stay that way! convert logo: -strip -set colorspace RGB \ -separate \ \( -clone 0 -poly ".1,-1" -poly "1,1.65" \) -swap 0,3 -delete 3 \ \( -clone 1 -poly ".1,-1" -poly "1,1.65" \) -swap 1,3 -delete 3 \ \( -clone 2 -poly ".1,-1" -poly "1,1.65" \) -swa...
by TedBaker
2017-11-12T18:41:06-07:00
Forum: Users
Topic: input Linear RGB specifiy output RGB or sRGB
Replies: 36
Views: 14424

Re: input Linear RGB specifiy output RGB or sRGB

Both these pages https://imagemagick.org/script/color-management.php and https://legacy.imagemagick.org/script/color-management.php the legacy and the current still have examples that are WRONG! convert myimage.png -separate myimage_channels_%d.png convert myimage_channels_*.png -combine myimage2.pn...
by TedBaker
2017-10-31T05:22:18-07:00
Forum: Digital Image Processing
Topic: Perform histogram analysis on certain image area only
Replies: 12
Views: 20382

Re: Perform histogram analysis on certain image area only

I see you have 6.8.9.9, but the patch date says 2017-07-31. That means it has been patched (though not to the current level/date). But I suspect it has botched patches for connected components. 6.8.9.9 per se is about 120 versions old. The first official debugged release was 6.8.9.10. I will take a...
by TedBaker
2017-10-30T16:50:49-07:00
Forum: Users
Topic: Finding vertical stipes to use for crop input
Replies: 5
Views: 2396

Re: Finding vertical stipes to use for crop input

I can get it close, but there may be false positives that you will have to filter by looking at the regularity of the gaps. Ok that's absolutely amazing, or should I say absolutely magic! The false positives should not a problem, to filter out as I can filter those out against the known aspect rati...
by TedBaker
2017-10-30T16:06:14-07:00
Forum: Users
Topic: Finding vertical stipes to use for crop input
Replies: 5
Views: 2396

Re: Finding vertical stripes to use for crop input

fmw42 wrote:
2017-10-30T16:02:05-07:00
Is this not just a repost of viewtopic.php?f=1&t=32821
No the problem is more specific, hence I thought it best to start a new topic.
by TedBaker
2017-10-30T15:47:44-07:00
Forum: Users
Topic: Finding vertical stipes to use for crop input
Replies: 5
Views: 2396

Finding vertical stipes to use for crop input

I have images of films strips from a scanner, like the following example. These, that have been nicely trimmed. https://ibb.co/dWDTbR I want to find the horizontal coordinates of the separating strips, i.e. the continues grey areas separating each frame. I want to use the horizontal coordinates to d...
by TedBaker
2017-10-27T10:52:10-07:00
Forum: Digital Image Processing
Topic: Colorspace When to convert?
Replies: 6
Views: 14880

Re: Colorspace When to convert?

Thanks,

Am I correct in my understanding that converting wider gammut colorspace like ProPhoto --> sRGB is losefull?

i.e. Profoto --> sRGB --> Profoto will result in some clipping if the original colours are "wider" than what can be translated into sRGB space.
by TedBaker
2017-10-27T06:40:42-07:00
Forum: Developers
Topic: 6.9.9-20 and 7.0.7-8 tags
Replies: 2
Views: 6079

Re: 6.9.9-20 and 7.0.7-8 tags

thanks I grab those now.
by TedBaker
2017-10-26T13:39:06-07:00
Forum: Digital Image Processing
Topic: Colorspace When to convert?
Replies: 6
Views: 14880

Re: Colorspace When to convert?

fmw42 wrote:
2017-10-26T10:16:59-07:00
Other formats such as PNG or TIFF (not JPG compress) should have no loss.
Where could I find a summary of the logic to convert

Linear RGB --> sRGB and
sRGB -> linear RGB

?
by TedBaker
2017-10-26T10:08:29-07:00
Forum: Digital Image Processing
Topic: Colorspace When to convert?
Replies: 6
Views: 14880

Colorspace When to convert?

I am struggling with a few concepts around colorspace, and profiles etc. I have implemented a transformations that relies on a linear RGB input. (An inversion of a negative film scan) The output from this transformation is to be further processed by other tools, ideally Rawtherapee. Rawtherapee inte...
by TedBaker
2017-10-23T06:29:17-07:00
Forum: Users
Topic: input Linear RGB specifiy output RGB or sRGB
Replies: 36
Views: 14424

Re: input Linear RGB specifiy output RGB or sRGB

I will report the issue. It should read: Normally, the conversion to separate each channel of an sRGB color image produces separate non-linear grayscale images. However the same concept can be applied, if it is desired to keep the separate channels as linear grayscale. For example, the following pr...