The Histogram Plugin will function as it did but a new feature has been added and checked into GIT. The one default that has been changed is that you can choose a Linear or a Log slider value. It is set at the beginning to 50% but if you want it to be the same as before, just set that slider all the way to Log. The easiest general procedure is to select the area on the timeline for which you would like to see the Histogram averaged and then click on the "Frames" button in the Histogram plugin. Description of other changes: Linear to Log slider - frequency in Linear range to Log range; default is 50%; original was always Log. Frames button - if a Selection is set on the timeline, the number of frames will be calculated and shown in the box next to it. Frame Count box - type in the number of frames you want to be looked at starting at the insert marker or use the up/down counter. Clear Frames icon - reset the frame count to the default value of 0. A side note - by using a number of frames, you can get a "dissolve-like transition effect" which is interesting.
Can you confirm that this new feature on the Histogram Plugin is compatible with the old/current projects? Thanks! IgorBeg Il 20/09/2020 02:06, Phyllis Smith via Cin ha scritto:
The Histogram Plugin will function as it did but a new feature has been added and checked into GIT. The one default that has been changed is that you can choose a Linear or a Log slider value. It is set at the beginning to 50% but if you want it to be the same as before, just set that slider all the way to Log.
The easiest general procedure is to select the area on the timeline for which you would like to see the Histogram averaged and then click on the "Frames" button in the Histogram plugin. Description of other changes:
Linear to Log slider - frequency in Linear range to Log range; default is 50%; original was always Log. Frames button - if a Selection is set on the timeline, the number of frames will be calculated and shown in the box next to it. Frame Count box - type in the number of frames you want to be looked at starting at the insert marker or use the up/down counter. Clear Frames icon - reset the frame count to the default value of 0.
A side note - by using a number of frames, you can get a "dissolve-like transition effect" which is interesting.
Thanks, great addition. But I must understand how it works. I had a crash during a reset, but I could not replicate it anymore.
All: The "Linear to Log Slider" is missing in the previous png file - I resized the window and did not notice this bug which GG will fix when he gets back from his bike ride. Andrea: I will explain better and provide a demo, hopefully sometime today. On Sun, Sep 20, 2020 at 8:06 AM Andrea paz via Cin < [email protected]> wrote:
Thanks, great addition. But I must understand how it works. I had a crash during a reset, but I could not replicate it anymore. -- Cin mailing list [email protected] https://lists.cinelerra-gg.org/mailman/listinfo/cin
A demo to go with an explanation. https://streamable.com/h0rzo5 The histogram plugin ordinarily applies a value for a single frame. This new feature modifies histogram to show values for a selection of frames. You use several frames in a video that you want to use the *"average"* color to determine the color you want the rest of the video to be. When there is a large light or color variation within a range of a few frames, you spend a lot of time correcting each frame when it would be better to just get an average value to use. If you want, then you can make a LUT for that set of frames instead of each frame. Thanks, great addition. But I must understand how it works.
I hope this helps, but I need a better understanding myself. Phyllis
Of note though is that the "Linear to Log Slider" will look different until you slide it all the way to LOG which is what it was in the original Histogram. Adding the Linear and the percentages for sliding provides the capability to see a more versatile histogram. Due to my little time to test, I ask you,... If I open an old project where there are Histogram plugin on the tracks, does my Project work as it was before?
Histogram is a tool very common in other Graphics/Photo (DigiKam, RawTherapee, Gimp) and NLEs programs, because very useful to Color Correction. Has anyone made a comparison (with the same frame, or image) to have a homogeneus result? I hope You understand what I mean. (really bad English) :-/ Thanks! IgorBeg
IgorBeg,
Of note though is that the "Linear to Log Slider" will look different
until you slide it all the way to LOG which is what it was in the original Histogram. Adding the Linear and the percentages for sliding provides the capability to see a more versatile histogram. Due to my little time to test, I ask you,... If I open an old project where there are Histogram plugin on the tracks, does my Project work as it was before?
Histogram is a tool very common in other Graphics/Photo (DigiKam, RawTherapee, Gimp) and NLEs programs, because very useful to Color Correction. Has anyone made a comparison (with the same frame, or image) to have a homogeneus result? I hope You understand what I mean. (really bad English) :-/
I guess I did not make this very clear in my previous png or demo. The correction in past projects will stay exactly the same. The only potential difference you will see is in the histogram graph itself -- not the image. For example, see the attached jpg file where the Slider is at Log, then 50%, then Linear. You see to the right in the orange/red Compositor sample that the color correction is exactly the same.
Thank you so much Phyllis, for the info and your time! I have done very quickly test about Histogram with Cin_20200920_release by git. My considerations and comparison (Preferences/Color/YUV color space= BT709/JPEG): Histogram Bezier plugin uses Log instead of Linear. I don't understand what type of histogram View Scope tool uses in its Histogram? Log, Linear or 50%? When the Color Model format (in Settings->Format...) is set to RGB[A] the histogram displayed on Histogram plugins is the same as on Histogram Bezier plugin. If you change Color Model format from RGB[A] to YUV[A] the histogram on Histogram Bezier no changes, but on Histogram plugin and on View Scopes it changes. It is strange, I think. In Histogram Bezier plugin the histogram doesn't change in the differents color model. Any yours considerations about? Thanks! IgorBeg Il 22/09/2020 05:43, Phyllis Smith via Cin ha scritto:
I guess I did not make this very clear in my previous png or demo. The correction in past projects will stay exactly the same. The only potential difference you will see is in the histogram graph itself -- not the image. For example, see the attached jpg file where the Slider is at Log, then 50%, then Linear. You see to the right in the orange/red Compositor sample that the color correction is exactly the same.
@Phyllis I'll wait a little bit more before updating the manual on Histogram plugin. Is it ok?
IgorBeg: Histogram Bezier plugin uses Log instead of Linear.
That is correct per GG.
I don't understand what type of histogram View Scope tool uses in its Histogram? Log, Linear or 50%?
He says "Log".
When the Color Model format (in Settings->Format...) is set to RGB[A] the histogram displayed on Histogram plugins is the same as on Histogram Bezier plugin. If you change Color Model format from RGB[A] to YUV[A] the histogram on Histogram Bezier no changes, but on Histogram plugin and on View Scopes it changes. It is strange, I think.
He is looking at the code this afternoon and so far reports that the calculation is done a little differently in Histogram Bezier than the other 2. But still looking and I am not sure I will be able to convey what the difference is.
IgorBeg, GG thoroughly reviewed the Histogram code to understand how it works so he could find any bugs. He says it is all working correctly as far as he can tell. But about the following:
When the Color Model format (in Settings->Format...) is set to RGB[A] the histogram displayed on Histogram plugins is the same as on Histogram Bezier plugin. If you change Color Model format from RGB[A] to YUV[A] the histogram on Histogram Bezier no changes, but on Histogram plugin and on View Scopes it changes. It is strange, I think. In Histogram Bezier plugin the histogram doesn't change in the differents color model.
we see in https://streamable.com/vr5srs that Histogram Bezier DOES CHANGE between the formats of RGBA and YUVA (note that I have set the slider all the way to Log in order to compare the same thing). You have to watch the Histogram Bezier graph specifically, but you definitely see it change. If I am misunderstanding the concern, please let me know.
Thanks Phyllis for your tests and GG for looking for. I don't think you are misunderstanding. I saw your video. I think it depends a bit from the video you are using for the test: your clip is an animation. I can wrong. In your screencast the histogram, in the Histogram Bezier, changes very, very, little. Please, take a look at my screencast: https://streamable.com/3svwkd As you can see, the histogram, in the Histogram Bezier, doesn't change as in the Histogram. More, you can see that when I enable the Histogram Bezier plugin a little change occurs in the histogram of the View Scope. Mmh, very strange. It is like if Histogram Bezier changes the Color Model of the project, but I am guessing. I am not saying it is "wrong", I think that it is really weird that tools that perform the same function (draw an histogram) don't show the same output, I would think. IgorBeg Il 27/09/2020 03:05, Phyllis Smith via Cin ha scritto:
IgorBeg, GG thoroughly reviewed the Histogram code to understand how it works so he could find any bugs. He says it is all working correctly as far as he can tell.
But about the following:
When the Color Model format (in Settings->Format...) is set to RGB[A] the histogram displayed on Histogram plugins is the same as on Histogram Bezier plugin. If you change Color Model format from RGB[A] to YUV[A] the histogram on Histogram Bezier no changes, but on Histogram plugin and on View Scopes it changes. It is strange, I think. In Histogram Bezier plugin the histogram doesn't change in the differents color model.
we see in https://streamable.com/vr5srs that Histogram Bezier DOES CHANGE between the formats of RGBA and YUVA (note that I have set the slider all the way to Log in order to compare the same thing). You have to watch the Histogram Bezier graph specifically, but you definitely see it change. If I am misunderstanding the concern, please let me know.
The reason for the different appearance in the histogram displays is that the value used in each case is not really the same kind of answer. A histogram is a bunch of "bins" (accumulators) that count the number of times a particular pixel channel intensity occurs in an image. Dim are on the left, bright on the right. The number of bins used depends on the color model bit depth, histogram: 256 for rgb8 and 65536 for all others. bezier: 256 for rgb8/yuv8 and 65536 for all others. scope: always uses 65536 All of the bins are scanned when the graph is plotted. What is shown depends on which plugin is used. histogram: was max of the bins in the pixel range, now is the sum bezier: is the max of the bins in the pixel range scope: is the max of the bins in the pixel range When the color space and the bin size are the same, all of the values increment the indexed bins. When the color is the result of yuv->rgb conversion, the results "spread" if there are more bins than colors. This is the same effect you see when you turn on "smoothing" in the vectorscope histogram. The "total" pixels for each value is approximately the same, but the "max" value depends on the color quantization. More colors increment more bins. Fewer colors increment fewer bins. In both cases, the image size has the same number of pixels. The fewer color case increments the used bins, and skips the unused bins. This sums all of the pixels into fewer bins, and the bins have higher values. That is the "rgb" vs "yuv" case, fewer vs more bins are used. To report something more consistent, I have changed the reported value to the "sum" of the accumulated counts for the bins reporting a pixel bar on the graph. The effect of this is to do this: 1 1 1 000100 3 pixels vs 0011000 3 pixels On the left, the course color model piles all 3 pixels into one bin. max value 3 On the right, the fine color model puts the counts into 2 bins, max 2, sum 3 So, by reporting the sum the shape of the results are more similar. gg On Sun, Sep 27, 2020 at 4:02 AM Igor BEGHETTO via Cin < [email protected]> wrote:
Thanks Phyllis for your tests and GG for looking for. I don't think you are misunderstanding. I saw your video. I think it depends a bit from the video you are using for the test: your clip is an animation. I can wrong. In your screencast the histogram, in the Histogram Bezier, changes very, very, little. Please, take a look at my screencast: https://streamable.com/3svwkd As you can see, the histogram, in the Histogram Bezier, doesn't change as in the Histogram.
More, you can see that when I enable the Histogram Bezier plugin a little change occurs in the histogram of the View Scope. Mmh, very strange. It is like if Histogram Bezier changes the Color Model of the project, but I am guessing.
I am not saying it is "wrong", I think that it is really weird that tools that perform the same function (draw an histogram) don't show the same output, I would think.
IgorBeg
Il 27/09/2020 03:05, Phyllis Smith via Cin ha scritto:
IgorBeg, GG thoroughly reviewed the Histogram code to understand how it works so he could find any bugs. He says it is all working correctly as far as he can tell.
But about the following:
When the Color Model format (in Settings->Format...) is set to RGB[A] the histogram displayed on Histogram plugins is the same as on Histogram Bezier plugin. If you change Color Model format from RGB[A] to YUV[A] the histogram on Histogram Bezier no changes, but on Histogram plugin and on View Scopes it changes. It is strange, I think. In Histogram Bezier plugin the histogram doesn't change in the differents color model.
we see in https://streamable.com/vr5srs that Histogram Bezier DOES CHANGE between the formats of RGBA and YUVA (note that I have set the slider all the way to Log in order to compare the same thing). You have to watch the Histogram Bezier graph specifically, but you definitely see it change. If I am misunderstanding the concern, please let me know. -- Cin mailing list [email protected] https://lists.cinelerra-gg.org/mailman/listinfo/cin
Thank you so much GG, for your exhaustive explanation!
This is the same effect you see when you turn on "smoothing" in the vectorscope histogram. The Smoothing feature is a good feature but I don't like as it works because, I think (and maybe I wrong ), it "false" what I am seeing. For me these tools are (should be) like a Oscilloscope instrument (or a multimeter, if you want): if the signal is a Sin wave 1Vpp@1kHz the instrument should show me that. But, I understand that here it is a bit different.
The fewer color case increments the used bins, and skips the unused bins. This sums all of the pixels into fewer bins, and the bins have higher values I don't understand this. You said: "More colors increment more bins. Fewer colors increment fewer bins."
To report something more consistent, I have changed the reported value to the "sum" of the accumulated counts for the bins reporting a pixel bar on the graph. Good explain, with the pile "graph".
I would like to do more tests about, from user point of view, to understand what diffences there are from Photography programs. I don't know what algorithm use the other NLE's and Graphic softwares, so I can not help on that. Sorry. GG, really thanks for your time! IgorBeg
@Igor BEGHETTO <[email protected]> Yes, Yes, I can. See the attached png file. Note that the project was created from a June 20, 2020 build (see the bottom section) and the project was loaded on a build of September 18. The color picker in the Compositor shows the exact same value and the image colors look equivalent. Of note though is that the "Linear to Log Slider" will look different until you slide it all the way to LOG which is what it was in the original Histogram. Adding the Linear and the percentages for sliding provides the capability to see a more versatile histogram. GG says something about the lower colors are washed out of the histogram or the higher colors are too prevalent when using LOG (this is probably quoted wrong) -- that is why it is set to the default of 50% until you change it. Note, that for illustrative purposes I have the slider set to LINEAR. On Sun, Sep 20, 2020 at 1:46 AM Igor BEGHETTO via Cin < [email protected]> wrote:
Can you confirm that this new feature on the Histogram Plugin is compatible with the old/current projects? Thanks!
IgorBeg
Il 20/09/2020 02:06, Phyllis Smith via Cin ha scritto:
The Histogram Plugin will function as it did but a new feature has been added and checked into GIT. The one default that has been changed is that you can choose a Linear or a Log slider value. It is set at the beginning to 50% but if you want it to be the same as before, just set that slider all the way to Log.
The easiest general procedure is to select the area on the timeline for which you would like to see the Histogram averaged and then click on the "Frames" button in the Histogram plugin. Description of other changes:
Linear to Log slider - frequency in Linear range to Log range; default is 50%; original was always Log. Frames button - if a Selection is set on the timeline, the number of frames will be calculated and shown in the box next to it. Frame Count box - type in the number of frames you want to be looked at starting at the insert marker or use the up/down counter. Clear Frames icon - reset the frame count to the default value of 0.
A side note - by using a number of frames, you can get a "dissolve-like transition effect" which is interesting. -- Cin mailing list [email protected] https://lists.cinelerra-gg.org/mailman/listinfo/cin
participants (4)
-
Andrea paz -
Good Guy -
Igor BEGHETTO -
Phyllis Smith