{"id":9098,"date":"2011-01-29T00:11:10","date_gmt":"2011-01-29T00:11:10","guid":{"rendered":"https:\/\/groupeastronomiespa.be\/astrogas\/orion-comment-ameliorer-orion-how-to-improve\/"},"modified":"2025-06-08T22:47:38","modified_gmt":"2025-06-08T20:47:38","slug":"orion-comment-ameliorer-orion-how-to-improve","status":"publish","type":"post","link":"https:\/\/groupeastronomiespa.be\/astrogas\/orion-comment-ameliorer-orion-how-to-improve\/","title":{"rendered":"Orion, comment am\u00e9liorer \/ Orion, how to improve?"},"content":{"rendered":"

Bonjour, j’ai trouv\u00e9 cette image sur un forum avec la mention \u00ab\u00a0Comment am\u00e9liorer?\u00a0\u00bb
\nPar le pass\u00e9, de telles images me laissaient perplexe.<\/p>\n

Hello, I found this pic on a forum with a mention \u00ab\u00a0How to improve?\u00a0\u00bb
\nI have seen such pics in the past and I was puzzled.<\/em><\/p>\n

Voici l’originale post\u00e9e en format png 8 bits:
\nHere is the originally posted pic, in png format, 8bits:<\/em>
\n\"\"<\/a><\/p>\n

La premi\u00e8re chose consiste \u00e0 se d\u00e9barrasser de ce fond de ciel par une fonction d’\u00e9galisation des bas niveaux de chaque canal RGB:
\nThe first step is to get rid of this sky background by equalizing the low level of each RGB channel:<\/em>
\n\"\"<\/a><\/p>\n

V\u00e9rifier le fond de ciel en ajustant les niveaux de visualisation; les coins sont plus sombres:
\nCheck the background by adjusting the visualization levels; the corners are darker:<\/em>
\n\"\"<\/a><\/p>\n

Pour me rendre la vie facile sur cette image, j’\u00e9limine les coins sombres par rognage \ud83d\ude41
\nTo make my life easier on this image, I remove the dark edges by cropping \ud83d\ude41<\/em>
\n\"\"<\/a><\/p>\n

OK, maintenant, je peux \u00e9galiser le fond de ciel et esp\u00e9rer moins d’influence de mauvaises parties de l’image:
\nOK, now I can equalize the background, hoping less influence of bad portions of the picture:<\/em>
\n\"\"<\/a><\/p>\n

V\u00e9rifions maintenant ce que nous avons dans cette image; les ailes de la n\u00e9buleuse sont assez faibles et le coeur est br\u00fbl\u00e9:
\nLet\u2019s check now what we have in this pic; the wings are quite faint and the heart is burned:<\/em>
\n\"\"<\/a><\/p>\n

V\u00e9rifions la r\u00e9partition des niveaux \u00e0 travers la n\u00e9buleuse:
\nLet\u2019s check the level distribution through the nebulae:<\/em>
\n\"\"<\/a><\/p>\n

Appliquons la technique des courbes pour augmenter les bas niveaux proportionnellement plus que les hauts niveaux:
\nLet\u2019s applying the curve technique, in order to increase the low levels more than the high levels:<\/em>
\n\"\"<\/a><\/p>\n

Ce n’est pas assez; les bords de la n\u00e9buleuse ne sont pas enti\u00e8rement ressortis et le bruit de fond de ciel n’est pas encore g\u00eanant. Continuons d’appliquer les courbes:
\nIt is not enough; the borders of the nebulae don’t fully pop-up and the background noise is not yet annoying. Let\u2019s continue with curves:<\/em>
\n\"\"<\/a><\/p>\n

Le r\u00e9sultat est meilleur, mais les niveaux de l’image (voir hardcopy pr\u00e9c\u00e9dent) sont assez compress\u00e9s. Nous allons d’abord les \u00e9tendre avant de continuer le traitement:
\nIt looks better, but the levels (See previous hardcopy) are quite compressed. Let\u2019s stretch them first prior to any further treatment:<\/em>
\n\"\"<\/a><\/p>\n

Continuons les courbes, pour tirer le maximum d’information des bas niveaux:
\nLet\u2019s continue to apply curves, in order to take out the maximum of data from the low levels:<\/em>
\n\"\"<\/a><\/p>\n

Je ne suis pas tr\u00e8s satisfait du fond de ciel, qui n’est pas r\u00e9parti uniform\u00e9ment; je tente de l’\u00e9quilibrer par la fonction ‘FlattenBackground’:
\nI’m not happy with the sky background, which is uneven; I try to balance it with the ‘FlattenBackground’ function:<\/em>
\n\"\"<\/a><\/p>\n

Toujours pas satisfait, je diminue le fond de ciel par ajustement des bas niveaux:
\nStill not happy; I minimize the background by adjusting the low level:<\/em>
\n\"\"<\/a><\/p>\n

L’image est bruit\u00e9e; essayons de la rendre pr\u00e9sentable avec NeatImage:
\nThe picture is noisy; let\u2019s try to make it fit to be seen with NeatImage:<\/em>
\n\"\"<\/a><\/p>\n

D\u00e9termination automatique des niveaux de bruit:
\nAuto-detection of noise level:<\/em>
\n\"\"<\/a><\/p>\n

Pr\u00e9visualisation du d\u00e9bruitage sur une portion de l’image. Ouch, efficace, peut-\u00eatre m\u00eame trop…:
\nPreviewing of the denoising. Wouw, efficient, maybe even too much…:<\/em>
\n\"\"<\/a><\/p>\n

Il y a bien entendu moyen d’ajuster le d\u00e9bruitage; je vous laisse d\u00e9couvrir ces fonctions (bleu) par vous-m\u00eame. Voici seulement un essai de sharpening:
\nDenoising can for sure be adjusted; I let you discover this by yourself (Blue). Here, just a sharpening trial:<\/em>
\n\"\"<\/a><\/p>\n

Appliquer le d\u00e9filtrage\/sharpening sur toute l’image et sauver:
\nApply the denoising and sharpening on the complete picture and save:<\/em>
\n\"\"<\/a><\/p>\n

Voici le r\u00e9sultat. Je ne suis toujours pas satisfait du fond du ciel, mais le but est de montrer qu’on peut tirer de l’information hors de la soupe captur\u00e9e dans nos villes.
\nHere is the result. I’m still not satisfied with the sky background, but the target was to demonstrate that we can take information out of pictures captured within the soup spread over our cities.<\/em>
\n\"\"<\/a><\/p>\n

Un coup d\u2019\u0153il sur l\u2019horodatage des captures \u00e9cran montre que le traitement a dur\u00e9 22 minutes.
\nA check of the screenshot’s timestamps shows that the treatment has taken 22 minutes.<\/em><\/p>\n

Alexandre<\/p>\n\n\n

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\n Veuillez voter<\/span>\n <\/div>\n <\/div>\n","protected":false},"excerpt":{"rendered":"

Bonjour, j’ai trouv\u00e9 cette image sur un forum avec la mention \u00ab\u00a0Comment am\u00e9liorer?\u00a0\u00bb Par le pass\u00e9, de telles images me laissaient perplexe. Hello, I found this pic on a forum with a mention \u00ab\u00a0How to improve?\u00a0\u00bb I have seen such pics in the past and I was puzzled. Voici l’originale post\u00e9e en format png 8 […]<\/p>\n","protected":false},"author":16,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[3],"tags":[],"class_list":["post-9098","post","type-post","status-publish","format-standard","hentry","category-astrobricolage"],"_links":{"self":[{"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/posts\/9098","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/comments?post=9098"}],"version-history":[{"count":1,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/posts\/9098\/revisions"}],"predecessor-version":[{"id":12584,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/posts\/9098\/revisions\/12584"}],"wp:attachment":[{"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/media?parent=9098"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/categories?post=9098"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/groupeastronomiespa.be\/astrogas\/wp-json\/wp\/v2\/tags?post=9098"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}