Digital noise appears as random pixels covering details in certain areas or the entire frame. The noise is usually caused by a range of factors including low light shooting conditions, high sensor gain, electronic noise and interference as well as aggressive compression of photo/video data. Regardless of the source, digital noise can seriously degrade the visual quality of the footage.
Video/photo with less apparent noise usually looks better. One possible way to achieve that is to use the in-camera noise reduction when available. Another option is to apply noise reduction in post-processing. It may also be possible to combine these two. Which option to choose and why? We will discuss that in this article.
Camera power vs Computer power
First off, a camera processor has limited computing power and must get the work done in a very short amount of time. It will give you a quick noise reduction result, however, the quality of that noise reduction is limited by these factors. Your computer has much more computing power and it has no strict time constraints. So it can use much more complex algorithms to identify and eliminate the noise more accurately. Therefore if the quality of noise reduction is important, then doing it in post is potentially a good idea.
The noise reduction algorithms
The simplest noise reduction algorithms used in some cameras basically smooth out the image by averaging nearby pixels. This often leads to the loss of fine details and somewhat artificial look of the image. A bit more advanced algorithms differentiate areas with details from flat featureless areas and apply stronger noise reduction in featureless areas. This produces relatively noise-free flat areas, but details, moving stuff and edges of objects remain covered in noise. Both loss of fine details and partial removal of noise do not look very good in the photo and video.
Unlike in-cam noise reduction, Neat Image's and Neat Video’s algorithms reduce noise much more accurately, preserving fine details, and do that everywhere in the frame, not just in flat areas. The process starts with analyzing noise present in the image/video and finding the noisiest areas within a frame. Once the programs know what kind of noise your image/video has, they turn on the filter and like a very fancy sieve separates that noise from the actual details. The profile-based separation allows making the entire frame clean while maintaining fine details.
Once again, if the quality is important, then it is better to reduce noise using more sophisticated algorithms available in post.
As mentioned above, in order to separate noise from the image details Neat Video needs to analyze the noise present in the video. The program analyzes the noise taken from a featureless area without details to study the characteristics and intensity of “pure” noise. If you give Neat Video a clip that has been denoised by your camera’s built-in noise reduction, and so the featureless areas are already smooth, then the profiler will analyze those smooth areas and may get a wrong idea about the noise in that video. As flat areas have very little noise after the in-cam noise reduction, the program gets a sample that is not representative of the original noise that still covers the details. The accurate separation of noise from details is not possible in this case and the final result will not look as good as it could if Neat Video was applied alone, without the preceding in-cam noise reduction.
Of course, this scenario has been taken into account when creating Neat Video and we have introduced special tools, such as Generic Profiles and Profile Check, to save a clip even if there are no suitable areas for profiling. Those tools do work really good, but an accurate noise profile that has been built for the specific video could do even better.
To make your own editing life simpler it can be easier to just disable such in-cam noise reduction and let Neat Video handle noise reduction in post without any interference.
Pain from repeated noise
Repeated noise is a condition when the noise remains the same (static and not changing) or almost the same in two or more consecutive frames while the scene content of those frames changes. Some of the reasons why repeated noise can occur include in-cam noise reduction and aggressive video compression applied by a video codec in a camera.
The presence of repeated noise can make in-post noise reduction more complicated for you: you have to spend more time tweaking the filter settings to account for the repeated noise. It is possible to deal with that problem in Neat Video (using the Repeated Frames tool) but it is just easier to get great results when you have no repeated noise, to begin with.
If you can make your camera’s noise reduction and compression less aggressive, then that can prevent repeated noise.
Amount of control
If a camera offers some control over the noise reduction built into it, usually you can only choose between, for example, heavy, medium and light noise reduction. Sometimes you have an option to switch it off completely. At times there are only two setting: ON or OFF. Some basic cameras don’t allow you to control noise reduction at all. That is easy, convenient and doesn’t require additional knowledge or experience. Such simplicity also means that there aren’t many ways to control the noise reduction applied. For example, you can’t adjust how noise in different color channels is treated. You get what you get and there is no way to back off once the photo/video is shot, since the in-cam noise reduction is already baked-in to the image/video data. On the other hand, if you can disable the in-cam noise reduction (and increase the codec bitrate to better preserve the details and noise during compression), then you still have the freedom of applying noise reduction of your choice in post. What is important, that noise reduction done in post will work better as well, since the in-cam noise reduction and codec do not mess up the noise properties so much.
Switch it Off the right way
If you are lucky to have an option to switch off the in-cam noise reduction completely, then go for it, at least try it to see if you get better results in the end. Unfortunately, not all cameras allow to do that. Some cameras only allow to choose the amount of noise reduction applied, without a possibility to switch it off completely. In such a case choose the lowest amount of noise reduction possible. Consumer-grade cameras often don’t provide any way of controlling the in-cam noise reduction. If that is the case, then leave the noise reduction as it is and check if you can adjust bitrate.
Bitrate is the amount of bandwidth used to encode the photo/video data. A higher bitrate means more bandwidth and higher resulting accuracy of encoding. Setting the bitrate for example x2 higher than the default of your camera can dramatically improve the detail preservation and avoid repeated noise as well. Using higher bitrate essentially makes the image/video codec less aggressive.
Your camera may not always offer a direct way to adjust the bitrate used by the camera’s image/video codec. The built-in software may not offer such an option, but there may be third-party software tools that may be able to adjust the bitrate.
As mentioned earlier, aggressive compression can create problems such as repeated noise and detail loss. When you suspect that this is happening to your photos/video, try changing the codec or its settings to avoid or minimize repeated noise and loss of details.
To make your images and video look better try (1) to decrease or disable the camera noise reduction and (2) to increase the bitrate of the emaige/video codecs, if these options are offered in your camera. These measures can better preserve the original image/video data and help the post-processing tools such as Neat Image and Neat Video deliver better results faster and easier for you. Compare the results obtained in this scenario with those produced by the camera using the default settings and choose what you prefer.
Neat Image and Neat Video can be adjusted to your own liking. You can decide how much noise you want to remove if you prefer more or less noise in the luminance or color channels to be preserved. Also, both filters help you to fine-tune the noise profile for more accurate denoising. The noise reduction done in post-production can always be disabled if necessary. Even if the filtered clip has already been exported, you can go back to the edit, turn the denoiser off or re-adjust it and do another export. You have this option when the noise is kept intact by the camera.
In-cam noise reduction is a quick way to deal with noise in the image/video. However, it can reduce the quality of your image/video: you may lose some of the fine details. In-cam noise reduction and codec can also make it harder to remove the residual and repeated noise left behind.
Neat Video and Neat Image as in-post denoisers will take some of your time for adjusting filters and rendering, but the quality of the final product will be better. It can also help with flicker, jitter of details and some other problems you may run into, so you will be able to get a few birds with one stone.
We believe that it is better to use Neat Image and Neat Video instead of in-cam noise reduction to have your shots neat and noise-free. Try that and make your own choice.
Kelele ya dijiti inaonekana kama pixels random kufunika maelezo katika maeneo fulani au sura nzima. Sauti ya sauti ni kawaida husababishwa na sababu mbalimbali, ikiwa ni pamoja na hali ya chini ya mwanga, upanuzi wa sensor, kelele ya elektroniki na kuingiliana, pamoja na compression ya picha na video. Bila kujali chanzo, kelele ya dijiti yaweza kudhoofisha sana ubora wa picha. Video/picha yenye kelele kidogo kwa kawaida huonekana vizuri zaidi. Njia moja inayowezekana ya kufikia kwamba ni kutumia katika kamera kelele kupunguza wakati inapatikana. Chaguo jingine ni kutumia kupunguza kelele katika baada ya usindikaji. Huenda ikawa pia inawezekana kuchanganya mambo hayo mawili. Ni chaguo gani la kuchagua na kwa nini? Tutazungumzia jambo hilo katika makala hii. Kamera Power vs Computer Power: Kamera Processor ina nguvu ndogo ya kompyuta na lazima kupata kazi kufanyika katika muda mfupi sana. Kwa hivyo, kwa sababu ya athari za haraka za kupunguza kelele, ni muhimu kuzingatia kwamba kiwango cha kelele cha kawaida ni cha chini. Kompyuta yako ina nguvu zaidi ya kompyuta na haina vikwazo vikali vya wakati. Kwa hiyo inaweza kutumia algorithms ngumu zaidi kutambua na kuondoa kelele kwa usahihi zaidi. Kwa hiyo kama ubora wa kupunguza kelele ni muhimu, basi kufanya hivyo katika post ni uwezekano wa wazo nzuri. Algorithms ya kupunguza kelele Algorithms rahisi ya kupunguza kelele inayotumiwa katika kamera zingine kimsingi hupunguza picha kwa wastani wa pikseli zilizo karibu. Mara nyingi hilo husababisha kupotea kwa maelezo madogo-madogo na kuonekana kwa picha hiyo kuwa bandia. Algorithms kidogo zaidi ya juu kutofautisha maeneo na maelezo kutoka maeneo gorofa featureless na kutumia nguvu kupunguza kelele katika maeneo featureless. Hii inazalisha maeneo ya gorofa yasiyo na kelele, lakini maelezo, vitu vinavyohamia na kingo za vitu hubaki zimefunikwa na kelele. Wote hasara ya maelezo faini na kuondolewa sehemu ya kelele si kuangalia nzuri sana katika picha na video. Tofauti na kupunguza kelele katika kamera, Neat Picha na Neat Video's algorithms kupunguza kelele kwa usahihi zaidi, kuhifadhi maelezo faini, na kufanya hivyo kila mahali katika sura, si tu katika maeneo tambarare. Utaratibu huanza na kuchambua kelele zilizopo katika picha / video na kupata maeneo yenye kelele zaidi ndani ya fremu. Mara baada ya programu kujua nini aina ya kelele picha yako au video ina, wao kugeuka juu ya chujio na kama sieve fancy sana hutenganisha kelele kwamba kutoka maelezo halisi. Kutenganisha msingi wa profile inaruhusu kufanya sura nzima safi wakati kudumisha maelezo faini. Kwa mara nyingine tena, kama ubora ni muhimu, basi ni bora kupunguza kelele kwa kutumia algorithms zaidi ya kisasa inapatikana katika baada ya. Kama ilivyoelezwa hapo juu, ili kutenganisha kelele kutoka kwa maelezo ya picha, Neat Video inahitaji kuchambua kelele iliyopo kwenye video. Programu inachambua kelele kuchukuliwa kutoka eneo featureless bila maelezo ya kusoma sifa na nguvu ya "safi" kelele. Ikiwa unaonyesha video ambayo imepunguzwa na kupunguza kelele ya kamera yako, na kwa hivyo maeneo yasiyo na sifa tayari ni laini, basi mtengenezaji wa maelezo atatafakari maeneo hayo laini na anaweza kupata wazo lisilo sahihi juu ya kelele katika video hiyo. Kama maeneo gorofa kuwa na kelele kidogo sana baada ya in-cam kelele kupunguza, programu anapata sampuli ambayo si mwakilishi wa kelele ya awali ambayo bado inashughulikia maelezo. Kutenganisha kwa usahihi kwa kelele kutoka kwa maelezo haiwezekani katika kesi hii na matokeo ya mwisho hayatakuonekana vizuri kama ingeweza kutumika ikiwa Neat Video ilitumiwa peke yake, bila kupunguza kelele ya kabla ya kamera. Bila shaka, hali hii imechukuliwa wakati wa kuunda Video ya Neat na tumeanzisha zana maalum, kama vile Profile za Generic na Chunguza Profile, kuhifadhi kipande hata kama hakuna maeneo yanayofaa kwa ajili ya profiling. Vifaa hivyo vinafanya kazi vizuri sana, lakini maelezo sahihi ya kelele ambayo yamejengwa kwa video maalum inaweza kufanya vizuri zaidi. Ili kufanya maisha yako mwenyewe ya uhariri rahisi inaweza kuwa rahisi tu kuzima kama in-cam noise reduction na basi Neat Video kushughulikia noise reduction katika post bila kuingiliwa yoyote. "Kuna tatizo la ""ngurumo ya mara kwa mara"" ambapo sauti inabaki sawa (static na haina kubadilika) au karibu sawa katika picha mbili au zaidi mfululizo wakati mandhari ya picha hizo inabadilika." Baadhi ya sababu kwa nini kelele mara kwa mara inaweza kutokea ni pamoja na in-cam kelele kupunguza na mkusanyiko wa video ya fujo kutumika na video codec katika kamera. Kuwepo kwa kelele ya mara kwa mara inaweza kufanya katika-post kupunguza kelele ngumu zaidi kwa ajili yenu: lazima kutumia muda zaidi tweaking mipangilio filter kwa akaunti ya kelele ya mara kwa mara. Ni rahisi sana kuondoa tatizo hili kwa kutumia kifaa cha Repeat Frames, lakini ni rahisi zaidi kupata matokeo mazuri wakati hakuna kelele ya mara kwa mara. Kama unaweza kufanya kamera yako's kelele kupunguza na compression chini ya vurugu, basi kwamba inaweza kuzuia kelele mara kwa mara. Kama kamera inatoa baadhi ya udhibiti juu ya kupunguza kelele kujengwa ndani yake, kwa kawaida unaweza tu kuchagua kati ya, kwa mfano, nzito, kati na mwanga kupunguza kelele. Wakati mwingine una chaguo la kuizima kabisa. Nyakati nyingine kuna mipangilio miwili tu: ON au OFF. Baadhi ya kamera za msingi haziruhusu wewe kudhibiti kupunguza kelele wakati wote. Hiyo ni rahisi, rahisi na haina inahitaji maarifa ya ziada au uzoefu. Uwezo huo pia ina maana kwamba hakuna njia nyingi za kudhibiti kupunguza kelele kutumika. Kwa mfano, huwezi kurekebisha jinsi kelele katika njia tofauti za rangi hutendewa. Kwa sababu ya kuonekana kwa picha, hakuna njia ya kurudi nyuma mara tu picha au video imepigwa, kwani kupunguza kelele ndani ya kamera tayari imewekwa kwenye data ya picha au video. Kwa upande mwingine, kama unaweza disable in-cam kelele kupunguza (na kuongeza codec bitrate ili bora kuhifadhi maelezo na kelele wakati wa compression), basi bado una uhuru wa kutumia kelele kupunguza ya uchaguzi wako katika post. Kwa upande mwingine, kwa sababu ya kuondoa kelele, hii inaweza kuwa rahisi kwa sababu ya kuondoa kelele ya kamera na codec ya kamera. Kama wewe ni bahati ya kuwa na chaguo la kuzima kabisa in-cam noise reduction, basi kwenda kwa ajili yake, angalau kujaribu kuona kama wewe kupata matokeo bora katika mwisho. Kwa kusikitisha, si kamera zote zinazoruhusu kufanya hivyo. Baadhi ya kamera tu kuruhusu kuchagua kiasi cha kupunguza kelele kutumika, bila uwezekano wa kuzima kabisa. Katika kesi kama hiyo kuchagua kiasi cha chini ya kupunguza kelele iwezekanavyo. Kamera za kiwango cha watumiaji mara nyingi hazitoi njia yoyote ya kudhibiti upunguzaji wa kelele ndani ya kamera. Kama hiyo ni kesi, kisha kuondoka kupunguza kelele kama ni na kuangalia kama unaweza kurekebisha bitrate. Bitrate ni kiasi cha bandwidth kutumika encode picha / video data. Bitrate ya juu ina maana bandwidth zaidi na usahihi wa juu wa kuingiza. Kuweka bitrate kwa mfano x2 juu kuliko default ya kamera yako inaweza kwa kiasi kikubwa kuboresha kuhifadhi maelezo na kuepuka kelele mara kwa mara pia. Kutumia bitrate ya juu kimsingi hufanya picha / video codec chini ya vurugu. Kamera yako inaweza si daima kutoa njia ya moja kwa moja kurekebisha bitrate kutumika na kamera ya picha / video codec. Programu iliyojengwa ndani inaweza kutotoa chaguo kama hilo, lakini kunaweza kuwa na zana za programu za mtu wa tatu ambazo zinaweza kurekebisha bitrate. Kama ilivyoelezwa hapo awali, compression fujo inaweza kuunda matatizo kama vile kelele mara kwa mara na hasara ya maelezo. Wakati unafikiri kwamba hii ni kutokea kwa picha yako, jaribu kubadilisha codec au mipangilio yake ili kuepuka au kupunguza kelele mara kwa mara na kupoteza maelezo. Ili kufanya picha zako na video kuonekana bora kujaribu (1) kupunguza au kuzima kamera kelele kupunguza na (2) kuongeza bitrate ya codecs emacs video, kama chaguzi hizi ni zinazotolewa katika kamera yako. Hizi hatua inaweza bora kuhifadhi picha ya awali na video data na kusaidia baada ya usindikaji zana kama vile Neat Picha na Neat Video kutoa matokeo bora kwa kasi na rahisi kwa ajili yenu. Linganisha matokeo yaliyopatikana katika hali hii na yale yaliyotengenezwa na kamera kwa kutumia mipangilio ya default na uchague kile unachokipenda. Picha safi na Video safi inaweza kurekebishwa kwa ladha yako mwenyewe. Unaweza kuamua kiasi gani kelele unataka kuondoa kama wewe kupendelea zaidi au chini kelele katika mwangaza au rangi njia ya kuhifadhiwa. Pia, filters zote mbili kukusaidia kurekebisha profile kelele kwa denoising sahihi zaidi. Kupunguzwa kelele kufanyika katika baada ya uzalishaji inaweza daima kuwa disabled kama ni lazima. Hata kama filtered clip tayari imekuwa nje, unaweza kwenda nyuma ya hariri, kugeuka denoiser mbali au re-kurekebisha na kufanya kuuza nje nyingine. Una chaguo hili wakati kelele ni kuhifadhiwa intact na kamera. In-cam kelele kupunguza ni njia ya haraka ya kukabiliana na kelele katika picha / video. Hata hivyo, inaweza kupunguza ubora wa picha yako au video: unaweza kupoteza baadhi ya maelezo mazuri. In-cam kelele kupunguza na codec pia inaweza kufanya kuwa vigumu kuondoa mabaki na mara kwa mara kelele kushoto nyuma. Video ya Neat na Picha ya Neat kama denoisers katika-post itachukua baadhi ya muda wako kwa ajili ya kurekebisha filters na kutoa, lakini ubora wa bidhaa ya mwisho itakuwa bora. Pia inaweza kusaidia na flicker, jitter ya maelezo na baadhi ya matatizo mengine unaweza kukimbia katika, hivyo utakuwa na uwezo wa kupata ndege wachache na jiwe moja. Ni bora kutumia Neat Image na Neat Video badala ya kupunguza kelele ya ndani ya kamera ili picha zako ziwe safi na zisizo na kelele. Jaribu kufanya hivyo na ufanye uchaguzi wako mwenyewe.