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= Nouveautés du moteur de rendu 2.6 =
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__TOC__
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<br/><br/>
 +
This page is intended to quickly illustrate the main effects of rendering settings.
  
Deux algorithmes du moteur de rendu ont été retravaillés :
+
Settings can be separated into three parts: the blending, the cutting and the weightings. <br/>
* le mélangeur multiband a été recodé pour améliorer l'équilibrage couleur et corriger des cas d'utilisation aux limites.
+
* Blending defines how the pixels of each image will be merged.
* le découpage des images appelé anti-fantôme peut désormais prendre en compte la focal des images pour essayer de conserver un maximum de définition dans le rendu final.  
+
* Cutting defines how the picture's frontiers will be chosen.
 +
* Weightings allow selecting the most relevant pixels of each image.
  
== nouveau multiband ==
+
[[Image:Autopano 350 render blending presets adsettings en.png|Blending presets]]
 +
<br/><br/><br/>
  
Pour rappelle, le mélangeur multiband permet de mélanger la couleur globale des images (les basses fréquences) tout en conservant les détails de chacune (les hautes fréquences).
+
== Blending ==
  
Dans la plupart des cas le mélangeur 2.5 donne des résultats où les différentes images sont parfaitement équilibrées. Certaines prises de vu nécessitent de pousser le mélangeur au maximum de ces capacités ( paramètre 0 dans l'interface). Selon le contenu des images et le positionnement des zones de recouvrement le mélangeur peut faire apparaitre des artefacts indésirables.
+
This part mainly illustrates the Multiband blending, which is the most efficient and of which the effects are not always easy to understand. Here’s the role of each blending in brief:
 +
* If no blending is used, the last image becomes a priority and simply overwrites the others. This blending is not very useful but can provide certain artistic options.
 +
* Linear blending allows creating an average between the overlapping images.
 +
* Multiband blending allows blending the overall color of the images (low frequencies) while preserving the details of each (high frequencies). The level of the Multiband enables influencing on the strength of the overall color texture. Following paragraph illustrates the influence of this setting.
  
Sans entrer dans des détails trop techniques, un mélangeur multiband a besoin de générer des données à multiple résolutions (construction du pyramide laplacienne). La génération de ces données multi-résolution nécessite différents filtrages de l'image. L'amélioration du mélangeur 2.6 vient de l’amélioration de la qualité de ces filtrages. Dans le moteur 2.5 les filtres pouvaient agir localement sur un voisinage de 2 pixels alors que dans le moteur 2.6 les filtres travaillent sur un voisinage de 5 pixels.
 
  
Le niveau de mélange maximal est également mieux estimer. Si les informations des différentes images sont trop mélangées cela peut faire apparaitre un voile gris qui détériore la qualités du rendu.
+
=== Multiband levels ===
  
Voici en image deux cas d'amélioration du nouveau moteur.
+
Multiband blending enables therefore to mitigate the differences in the scale and/or the exposure existing between the juxtaposed images.  
  
Pour ce premier cas, les zones de recouvrement ne laissent pas beaucoup de choix pour le découpage des images et celui-ci est souvent effectué à proximité de la frontière entre la forêt et le ciel. Si l'analyse des détails des images est imprécise, l'utilisation d'un fort niveau de mélange va fusionner l'information du ciel avec celle de la forêt ce qui n'est pas souhaitable. Les niveaux maximum ont changé entre 2.5 et 2.6 mais nous avons pris soin d'utiliser des paramètres équivalent pour obtenir ces résultats.
+
The schema below illustrates how the blending is done from source photos of 4096 pixels wide (the Multiband level is defined by the value N). <br/>
 +
[[Image:Schema Muliband level en.png]]
  
{|
+
'''What is necessary to remember:'''
|-
+
* N = 0 : the ​​influence zone is equivalent to the total width of the image, so the blending is maximum.
| [[Image:multiband-1-2.5.jpg|left|thumb|900px]]
+
 
 +
* N = -1 : the ​​influence zone is equivalent to 1/2 of the real size of the image
 +
* N = -2 : the ​​influence zone is equivalent to 1/4 of the real size of the image
 +
* N = -3 : the ​​influence zone is equivalent to 1/8 (warning: logarithmic scale)
 +
* ... etc...
 +
 
 +
 
 +
* N = 1 : there is no blending (on about 2 pixel only)
 +
* N = 2 : blending on about 4 pixels wide
 +
* N = 3 : blending on about 8 pixels wide (warning: logarithmic scale)
 +
* ... etc...
 +
 
 +
 
 +
[[Image:Icon attention.png|16px]] '''Notes :''' <br/>
 +
* It is important to note that negative values ​​from -10 to 0 does not follow the positive values ​​from 1 to 10, as we should see on a logical standard suite of values.
 +
* For this case, the values -2 and 10 (for example) are illustrated on the same level: the logarithmic calculation make this 2 vlaues a similar result. That said, this is not necessarily true for photos whose size can not be defined to the power 2.
 +
* With this source image (4096 pixels), N reaches in fact the value 12 (Nmax = 12). The software limitations make that this value is not reachable this way (maximal positive value = 10), it is therefore possible to set the level to 0, equivalent to the level 12. This is not true all the time and changes depending on the source image and the rendering size (if it is not set at 100%). Then the example above is applicable for source images of 4096 pixels wide only.
 +
 
 +
 
 +
Here’s a simple example with these differences:
 +
 
 +
 
 +
* For this first rendering, the level is on 1 (setting equivalent to a simple linear blending and no balancing is therefore performed):
 +
[[Image:multiband-tournette-N1.jpg|800px|Level 1]]
 +
 
 +
 
 +
* For this second rendering, the level is greater (7) and we see that the balance around the boundaries between the images starts.
 +
[[Image:multiband-tournette-N7.jpg|800px|Level 7]]
 +
 
 +
 
 +
We can compare the notion of the level (Multiband level) with the scope of balancing information. The problem is that the required scope will depend on the size of the images and the panorama which is rendered. <br/>
 +
To overcome this, we must use negative values that define a spreading level which is relative to the maximum level possible.
 +
 
 +
 
 +
* This third rendering uses the default level (-2). Sharp differences in the exposure have completely disappeared.
 +
 
 +
[[Image:multiband-tournette-N-2.jpg|800px|Level -2]]
 +
 
 +
 
 +
* Here is a final rendering that uses the maximum level of blending, represented by the value 0. Each image is spread to maximize its medium shade and the panorama is fully balanced.
 +
 
 +
[[Image:multiband-tournette-N0.jpg|800px|Level 0]]
 +
<br/><br/><br/>
 +
 
 +
== Cutting ==
 +
 
 +
Different cutting methods allow you to select the content of each image.
 +
The '''Cutting''' algorithm will act on the data belonging to the same layer to find the best blend possible.
 +
 
 +
 
 +
=== Smart cutting ===
 +
 
 +
Smart cutting enables to make a binary option between the overlapping images to prevent potential blurring related to moving objects and/or remaining alignment errors. This cutting may consider two different concepts:
 +
* '''Remove ghosts''': the aim is to find the path between two images to minimize the differences at the borders. Most of the time, the result allows you to keep or eliminate the moving objects (ghosts) completely.
 +
* '''Preserves the long focal lengths''': the aim here is to maintain the image that has the best definition (the longest focal length).
 +
 
 +
 
 +
Note: The second setting is used to resolve stitching cases of multiple focal lengths shooting and it is highly recommended to leave the default settings if it is not the case.
 +
 
 +
 
 +
* Here’s an example of multiple focal lengths shooting :
 +
** Images have been modified slightly colorimetrically and Multiband is disabled in order to show the cutting option. <br/>
 +
** The aim is to maintain the image that has the best resolution in the final panorama which means the image that has the longest focal length. <br/>
 +
 
 +
 
 +
{| cellpadding="2" cellspacing="2" border="0" width="900px"
 +
|valign="top" align="center"  width="300px" | Project
 +
|valign="top" align="center"  width="300px" | Rendering after removing ghosts
 +
|valign="top" align="center"  width="300px" | Rendering with the long focal lenses
 
|-
 
|-
|valign="bottom" align="center" width="900px" | rendu 2.5
+
|valign="bottom" align="center" |[[Image:cutting-1.gif|300px]]
 +
|valign="bottom" align="center" |[[Image:cutting-1-ghost.jpg|300px]]
 +
|valign="bottom" align="center" |[[Image:cutting-1-focal.jpg|300px]]
 
|}
 
|}
  
{|
+
 
|-
+
It is clear that the Anti-ghost concept is not compatible with the conservation of long focal lengths concept. <br/>
| [[Image:multiband-1-2.6.jpg|left|thumb|900px]]
+
Indeed, the result is logical: the choice that minimizes the differences in borders is only to keep the image within short focal length which means to not to set any borders. <br/>
 +
In a simple case as that, the second setting which considers the focal fully meets expectations. <br/>
 +
But one must often compromise between the concept of maximum focal length and the minimum ghost because these two concepts can be contradictory.
 +
 
 +
 
 +
* Here is another example which illustrates the different cutting options according to different settings of cutting:
 +
 
 +
 
 +
{| cellpadding="2" cellspacing="2" border="0" width="900px"
 +
|valign="top" align="center"  width="300px" | project
 +
|valign="top" align="center"  width="300px" | rendering (Removal of ghosts))
 +
|valign="top" align="center"  width="300px" | rendering (Preserving long focal lenghts)
 +
|valign="top" align="center"  width="300px" | rendering (compromise between ghost and focal)
 
|-
 
|-
|valign="bottom" align="center" width="900px" | rendu 2.6
+
|valign="bottom" align="center" |[[Image:cutting-2.gif|300px]]
 +
|valign="bottom" align="center" |[[Image:cutting-2-ghost.jpg|300px]]
 +
|valign="bottom" align="center" |[[Image:cutting-2.focal.jpg|300px]]
 +
|valign="bottom" align="center" |[[Image:cutting-2-merge.jpg|300px]]
 
|}
 
|}
  
Il est clairement visible que lorsque l’algorithme est poussé au maximum le rendu 2.6 est moins sensible aux cas limites.
 
  
Ce second cas présente un dégradés dans le ciel du aux différences d'exposition des images sources. Les deux images sont obtenues avec des paramètres équivalent qui correspondent au profil de rendu "anti-fantôme").
+
We see that it is not always easy to keep the images of long focal length without adding errors in the moving objects. <br/>
 +
This is why it is recommended to leave the setting on Remove ghosts if the picture is not affected by problems of multiple focal lengths.
  
{|  
+
 
 +
=== Iso cutting ===
 +
 
 +
This cutting mode is new since version 3.5.
 +
 
 +
This cut will keep picture area which are closer to each picture centres. Unlike smart cutting, this new mode is not an anti-ghost mode. Picture contents will not be analysed. So, moving objects and parallax effects will not be well cut.
 +
 
 +
This new mode is used in Autopano Video to get a cutting which depends of picture position but not of contents for having a stable cutting along the time. But this mode can also be efficient for stitching pictures.
 +
 
 +
When stitching does not need anti-ghost algorithm (landscape stitching without parallax), the Iso cutting will allow that each picture will participate to final blending in equivalent proportions and will prevent to cut close to picture borders. These two conditions will make easier colour balancing done by the multiband blender.
 +
 
 +
Sample below will compare blending result between Smart and Iso cutting. Cutting mode of Autopano 3.0 (equivalent to current Smart mode) is also shown to illustrate Smart cutting improvements. Unlike 3.0 cutting, Smart cutting also try to not cut on picture borders when there is no real ghosting condition.
 +
 
 +
 
 +
{| cellpadding="2" cellspacing="2" border="0" width="950px"
 +
|valign="top" align="center"  width="50px" | '''Blending'''
 +
|valign="top" align="center"  width="300px" | '''Cutting 3.0'''
 +
|valign="top" align="center"  width="300px" | '''Iso'''
 +
|valign="top" align="center"  width="300px" | '''Smart'''
 
|-
 
|-
|[[Image:multiband-2-2.5.jpg|left|thumb|900px]]
+
|valign="center" align="center" | '''None'''
 +
|valign="bottom" align="center" |[[Image:3.0-cut-none.png|300px]]
 +
|valign="bottom" align="center" |[[Image:3.5-iso-none.png|300px]]
 +
|valign="bottom" align="center" |[[Image:3.5-smart-none.png|300px]]  
 
|-
 
|-
|valign="bottom" align="center" width="900px" | rendu 2.5
+
|valign="top" align="left" |
|}
+
|valign="top" align="left" | Erratic cutting
 
+
|valign="top" align="left" | Very regular cutting
{|  
+
|valign="top" align="left" | More regular cutting than 3.0
 
|-
 
|-
|[[Image:multiband-2-2.6.jpg|left|thumb|900px]]
+
|valign="center" align="center" | '''Multiband -2'''
 +
|valign="bottom" align="center" |[[Image:3.0-cut.png|300px]]
 +
|valign="bottom" align="center" |[[Image:3.5-iso.png|300px]]
 +
|valign="bottom" align="center" |[[Image:3.5-smart.png|300px]]
 
|-
 
|-
|valign="bottom" align="center" width="900px" | rendu 2.6
+
|valign="top" align="left" |
 +
|valign="top" align="left" | Some times, small visible frontiers stays even between pictures which have close exposition (left part of the sky) 
 +
|valign="top" align="left" | Large exposition differences stay visible but smallest are invisible
 +
|valign="top" align="left" | Result is more close to Iso mode than cutting 3.0 when there is no real ghosting situation
 
|}
 
|}
  
Grâce à l'élargissement des filtrages effectués dans le rendu 2.6, le mélange des informations est plus progressif et plus agréable. Pour information, en poussant un peu les paramètres du mélangeur le résultat est amélioré en 2.5 et devient parfait en 2.6. Néanmoins, nous conservons l'exemple avec les paramètres par défaut car les différences sont plus visibles.
+
To illustrate the propose, sample used has large exposition differences which where nor corrected. For information, this stitch becomes perfect by activating colour correction.  
  
== nouveau découpage des images ==
+
{| cellpadding="2" cellspacing="2" border="0" width="300px"
 +
|valign="bottom" align="center" |[[Image:3.5-smart-color.png|300px]]
 +
|}
 +
<br/><br/><br/>
  
Le découpage des images version 2.6 correspond à l'anti-fantôme de la version 2.5.
+
== Weightings ==
  
L’objectif de l'anti-fantôme est de trouver le chemin entre deux images qui minimise les différences aux frontières. Le résultat permet la plupart du temps de conserver ou d'éliminer entièrement les objets en mouvement (les fantômes).
+
Weightings methods allow to average pixels of different pictures. Unlike cutting methods which are making binary choices as illustrated before, weighting methods can be combined but they are not compatible with cutting algorithm. So, in most of cases cutting option must be set to none before to use weighting algorithms.  
  
Dans la version 2.6 l'anti-fantôme est remplacé par une notion plus générale de découpage qui peut être paramétrée. A noter que les paramètres par défaut du découpage 2.6 correspondent à l'anti-fantôme 2.5. Le nouveau paramètre permet de résoudre des cas d'assemblage de prise de vue multiple focal et il est fortement conseillé de laisser les paramètres par défaut si ça n'est pas le cas.
+
It can be useful to combine cutting and weighting algorithm only if you have several layers in Autopano. Cut algorithm will be applied inside each layers and weighting between layers. This this typical for blending bracketed picture, '''Exposure fusion''' and '''Remove HDR ghost''' tools will act between the layers (between the bracketed images) to select the most relevant pixels. These two notions are mainly HDR images and are shown in the page [[LDR / HDR : How it works|'''LDR / HDR : How it works''']].  
  
Voici un exemple de prise de vue multi focal. Les images ont été légèrement modifiées colorimétriquement et le multiband est désactivé afin de bien visualiser les choix de découpage.
 
L'objectif est de conserver l'image qui a la meilleure résolution dans le panorama final, c'est à dire l'image qui a la plus longue focal.
 
  
{| cellpadding="2" cellspacing="2" border="0" width="900px"
+
=== Diamond Weighting ===
|valign="bottom" align="center" |[[Image:cutting-1.gif|thumb|300px]]
+
|valign="bottom" align="center" |[[Image:cutting-1-ghost.jpg|thumb|300px]]
+
|valign="bottom" align="center" |[[Image:cutting-1-focal.jpg|thumb|300px]]
+
|-
+
|valign="top" align="center"  width="300px" | projet
+
|valign="top" align="center"  width="300px" | rendu avec suppresion des fantômes
+
|valign="top" align="center"  width="300px" | rendu avec conservation des longues focals
+
|}
+
  
On voit clairement que la notion d'anti-fantôme ne permet pas de résoudre notre problème. En effet, le résultat est logique : le choix qui minimise les différences aux frontières est pas de frontières du tout c'est à dire conserver l'image de petite focal uniquement.
+
In some quite specific cases, a clear cutting of juxtaposed images may be visible. <br/>
 +
This may cause difficulties in finding the cutting which minimizes the ghosts or even develop differences dividing it into strong differences in texture.
  
Dans un cas aussi simple, le nouveau paramètre de prise en compte de la focale répond parfaitement aux attentes. Mais il faudra souvent un compromis entre la notion de focal maximale et fantôme minimal car ces deux notions peuvent être contradictoires.
 
Voici un exemple qui illustre les différents choix de découpage selon les différents paramètres.
 
  
{| cellpadding="2" cellspacing="2" border="0" width="900px"
+
In such cases, the use of Diamond weighting can improve the rendering. This notion allows you to give the priority to central pixels of each image without entirely excluding the pixels of neighboring images. <br/>
|valign="bottom" align="center" |[[Image:cutting-2.gif|thumb|450px]]
+
Thus the transition is much smooth. On the other hand, this gives a much blurred texture to the final rendering.
|valign="bottom" align="center" |[[Image:cutting-2-ghost.jpg|thumb|450px]]
+
 
|-
+
 
|valign="top" align="center"  width="450px" | projet
+
{| cellpadding="2" cellspacing="2" border="0" width="800px"
|valign="top" align="center"  width="450px" | rendu avec suppression des fantômes
+
|valign="top" align="center"  width="300px" | cutting
|-  
+
|valign="top" align="center"  width="300px" | Diamond
|valign="bottom" align="center" |[[Image:cutting-2.focal.jpg|thumb|450px]]
+
|-
|valign="bottom" align="center" |[[Image:cutting-2-merge.jpg|thumb|450px]]
+
|valign="bottom" align="center" |[[Image:water-cut.jpg|400px]]
|-
+
|valign="bottom" align="center" |[[Image:water-diamond.jpg|400px]]
|valign="top" align="center"  width="450px" | rendu avec conservation des longues focals
+
|valign="top" align="center"  width="450px" | rendu avec un compromis entre fantôme et focals
+
 
|}
 
|}
  
On voit qu'il n'est pas toujours évident de conserver les images de grande focal sans ajouter d'erreurs au niveau des objets en mouvement.
+
 
C'est pour cela qu'il est conseillé laisser le paramètre sur anti-fantôme si le panorama n'est pas concerné par les problèmes de multiple focal.
+
The result is generally satisfactory only on certain parts of the panorama. We therefore recommend using this rendering mode in addition to a clear cut rendering and to manually merge the two results with an editor like Photoshop.
 +
 
 +
 
 +
=== Exposure fusion ===
 +
 
 +
Gives more importance to the well-exposed pixels of each image. <br/>
 +
The influence of this setting is shown [[LDR / HDR - Workflow case B|'''on this page''']]
 +
 
 +
 
 +
=== Removing HDR ghosts ===
 +
 
 +
Dims the importance of pixels of which the value is far from the majority of pixels in the same position, which means to mitigate the ghost effects in bracket mode (object which moved during the shooting of a same position). <br/>
 +
It may be better to disable this setting if there is no HDR ghost type (it can enhance the color differences existing between different positions).
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
 
 +
'''BACK TO:'''  [[Documentation]] / [[Autopano Documentation]]
 +
 
 +
[[fr:Comprendre et utiliser le moteur de rendu]]
 +
 
 +
[[Category:Autopano - Main Notions]]

Latest revision as of 13:41, 22 September 2015



This page is intended to quickly illustrate the main effects of rendering settings.

Settings can be separated into three parts: the blending, the cutting and the weightings.

  • Blending defines how the pixels of each image will be merged.
  • Cutting defines how the picture's frontiers will be chosen.
  • Weightings allow selecting the most relevant pixels of each image.

Blending presets


Blending

This part mainly illustrates the Multiband blending, which is the most efficient and of which the effects are not always easy to understand. Here’s the role of each blending in brief:

  • If no blending is used, the last image becomes a priority and simply overwrites the others. This blending is not very useful but can provide certain artistic options.
  • Linear blending allows creating an average between the overlapping images.
  • Multiband blending allows blending the overall color of the images (low frequencies) while preserving the details of each (high frequencies). The level of the Multiband enables influencing on the strength of the overall color texture. Following paragraph illustrates the influence of this setting.


Multiband levels

Multiband blending enables therefore to mitigate the differences in the scale and/or the exposure existing between the juxtaposed images.

The schema below illustrates how the blending is done from source photos of 4096 pixels wide (the Multiband level is defined by the value N).
Schema Muliband level en.png

What is necessary to remember:

  • N = 0 : the ​​influence zone is equivalent to the total width of the image, so the blending is maximum.
  • N = -1 : the ​​influence zone is equivalent to 1/2 of the real size of the image
  • N = -2 : the ​​influence zone is equivalent to 1/4 of the real size of the image
  • N = -3 : the ​​influence zone is equivalent to 1/8 (warning: logarithmic scale)
  • ... etc...


  • N = 1 : there is no blending (on about 2 pixel only)
  • N = 2 : blending on about 4 pixels wide
  • N = 3 : blending on about 8 pixels wide (warning: logarithmic scale)
  • ... etc...


Icon attention.png Notes :

  • It is important to note that negative values ​​from -10 to 0 does not follow the positive values ​​from 1 to 10, as we should see on a logical standard suite of values.
  • For this case, the values -2 and 10 (for example) are illustrated on the same level: the logarithmic calculation make this 2 vlaues a similar result. That said, this is not necessarily true for photos whose size can not be defined to the power 2.
  • With this source image (4096 pixels), N reaches in fact the value 12 (Nmax = 12). The software limitations make that this value is not reachable this way (maximal positive value = 10), it is therefore possible to set the level to 0, equivalent to the level 12. This is not true all the time and changes depending on the source image and the rendering size (if it is not set at 100%). Then the example above is applicable for source images of 4096 pixels wide only.


Here’s a simple example with these differences:


  • For this first rendering, the level is on 1 (setting equivalent to a simple linear blending and no balancing is therefore performed):

Level 1


  • For this second rendering, the level is greater (7) and we see that the balance around the boundaries between the images starts.

Level 7


We can compare the notion of the level (Multiband level) with the scope of balancing information. The problem is that the required scope will depend on the size of the images and the panorama which is rendered.
To overcome this, we must use negative values that define a spreading level which is relative to the maximum level possible.


  • This third rendering uses the default level (-2). Sharp differences in the exposure have completely disappeared.

Level -2


  • Here is a final rendering that uses the maximum level of blending, represented by the value 0. Each image is spread to maximize its medium shade and the panorama is fully balanced.

Level 0


Cutting

Different cutting methods allow you to select the content of each image. The Cutting algorithm will act on the data belonging to the same layer to find the best blend possible.


Smart cutting

Smart cutting enables to make a binary option between the overlapping images to prevent potential blurring related to moving objects and/or remaining alignment errors. This cutting may consider two different concepts:

  • Remove ghosts: the aim is to find the path between two images to minimize the differences at the borders. Most of the time, the result allows you to keep or eliminate the moving objects (ghosts) completely.
  • Preserves the long focal lengths: the aim here is to maintain the image that has the best definition (the longest focal length).


Note: The second setting is used to resolve stitching cases of multiple focal lengths shooting and it is highly recommended to leave the default settings if it is not the case.


  • Here’s an example of multiple focal lengths shooting :
    • Images have been modified slightly colorimetrically and Multiband is disabled in order to show the cutting option.
    • The aim is to maintain the image that has the best resolution in the final panorama which means the image that has the longest focal length.


Project Rendering after removing ghosts Rendering with the long focal lenses
Cutting-1.gif Cutting-1-ghost.jpg Cutting-1-focal.jpg


It is clear that the Anti-ghost concept is not compatible with the conservation of long focal lengths concept.
Indeed, the result is logical: the choice that minimizes the differences in borders is only to keep the image within short focal length which means to not to set any borders.
In a simple case as that, the second setting which considers the focal fully meets expectations.
But one must often compromise between the concept of maximum focal length and the minimum ghost because these two concepts can be contradictory.


  • Here is another example which illustrates the different cutting options according to different settings of cutting:


project rendering (Removal of ghosts)) rendering (Preserving long focal lenghts) rendering (compromise between ghost and focal)
Cutting-2.gif Cutting-2-ghost.jpg Cutting-2.focal.jpg Cutting-2-merge.jpg


We see that it is not always easy to keep the images of long focal length without adding errors in the moving objects.
This is why it is recommended to leave the setting on Remove ghosts if the picture is not affected by problems of multiple focal lengths.


Iso cutting

This cutting mode is new since version 3.5.

This cut will keep picture area which are closer to each picture centres. Unlike smart cutting, this new mode is not an anti-ghost mode. Picture contents will not be analysed. So, moving objects and parallax effects will not be well cut.

This new mode is used in Autopano Video to get a cutting which depends of picture position but not of contents for having a stable cutting along the time. But this mode can also be efficient for stitching pictures.

When stitching does not need anti-ghost algorithm (landscape stitching without parallax), the Iso cutting will allow that each picture will participate to final blending in equivalent proportions and will prevent to cut close to picture borders. These two conditions will make easier colour balancing done by the multiband blender.

Sample below will compare blending result between Smart and Iso cutting. Cutting mode of Autopano 3.0 (equivalent to current Smart mode) is also shown to illustrate Smart cutting improvements. Unlike 3.0 cutting, Smart cutting also try to not cut on picture borders when there is no real ghosting condition.


Blending Cutting 3.0 Iso Smart
None 3.0-cut-none.png 3.5-iso-none.png 3.5-smart-none.png
Erratic cutting Very regular cutting More regular cutting than 3.0
Multiband -2 3.0-cut.png 3.5-iso.png 3.5-smart.png
Some times, small visible frontiers stays even between pictures which have close exposition (left part of the sky) Large exposition differences stay visible but smallest are invisible Result is more close to Iso mode than cutting 3.0 when there is no real ghosting situation

To illustrate the propose, sample used has large exposition differences which where nor corrected. For information, this stitch becomes perfect by activating colour correction.

3.5-smart-color.png




Weightings

Weightings methods allow to average pixels of different pictures. Unlike cutting methods which are making binary choices as illustrated before, weighting methods can be combined but they are not compatible with cutting algorithm. So, in most of cases cutting option must be set to none before to use weighting algorithms.

It can be useful to combine cutting and weighting algorithm only if you have several layers in Autopano. Cut algorithm will be applied inside each layers and weighting between layers. This this typical for blending bracketed picture, Exposure fusion and Remove HDR ghost tools will act between the layers (between the bracketed images) to select the most relevant pixels. These two notions are mainly HDR images and are shown in the page LDR / HDR : How it works.


Diamond Weighting

In some quite specific cases, a clear cutting of juxtaposed images may be visible.
This may cause difficulties in finding the cutting which minimizes the ghosts or even develop differences dividing it into strong differences in texture.


In such cases, the use of Diamond weighting can improve the rendering. This notion allows you to give the priority to central pixels of each image without entirely excluding the pixels of neighboring images.
Thus the transition is much smooth. On the other hand, this gives a much blurred texture to the final rendering.


cutting Diamond
Water-cut.jpg Water-diamond.jpg


The result is generally satisfactory only on certain parts of the panorama. We therefore recommend using this rendering mode in addition to a clear cut rendering and to manually merge the two results with an editor like Photoshop.


Exposure fusion

Gives more importance to the well-exposed pixels of each image.
The influence of this setting is shown on this page


Removing HDR ghosts

Dims the importance of pixels of which the value is far from the majority of pixels in the same position, which means to mitigate the ghost effects in bracket mode (object which moved during the shooting of a same position).
It may be better to disable this setting if there is no HDR ghost type (it can enhance the color differences existing between different positions).








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