Ceci est une ancienne révision du document !
This series is aimed at learning to make something of the old photos in my possession, and others in the public domain due to their age. You, the reader, are welcome to tag along, and, I hope, glean some small insight and perhaps an idea or two from time to time. No promises are made as to quality of the content, or potential errors and omissions. I am a computer scientist, not a true artist or a professional of image restoration. So please take all this as a best effort, but with no firm guarantees — much as is the case of most open-source software. In the previous part of this series, we colorized a studio portrait of Paul Trapper, dating from about 1915. In this part, we will be working on another portrait – but this one will not be a photographer’s work from the early 20th century ,but, rather, a very typical effort from the late 1970s when technology had changed and color photography had become more commonplace.
Cette série a pour but d'apprendre à faire quelque chose des vieilles photos en ma possession, ainsi que d'autres du domaine public du fait de leur âge. Vous, lecteur, êtes bienvenu pour m'accompagner et, j'espère, glaner quelques petites particularités et une idée ou deux de temps à autre. Je ne fais aucune promesse sur la qualité du contenu, ou sur les erreurs et omissions possibles. Je suis un scientifique en informatique, pas un artiste ou un vrai professionnel de la restauration des images. Aussi, merci de considérer ça comme mon meilleur effort, mais sans garanties fermes, comme c'est souvent le cas dans les logiciels Open Source.
Dans la partie précédente de cette série, nous avons colorisé un portrait en studio de Paul Trappen, datant de 1915 environ. Dans cette aprtie, nous travaillerons sur un autre portrait – mais celui-ci ne sera pas un travail de photogrpahe, mais, plutôt, une vraie tentative typique de la fin des années 70 quand la technologie changea et que la photographie couleur devint plus courante.
This photo was taken by a member of my family, in 1979 or thereabouts, and using a typical 35 mm reflex camera. As was often the case at the time, color photographic film had a slightly better response to red light than to green or blue, and this shows up in the final print. In addition, some chemical alterations may have taken place during the intervening years even though care has been taken to store and preserve the print. This will be the case for most family pictures from the time; some years later on, better quality photographic film was available and color dominance was not so much of an issue in the late 1990s or early 2000s – which is when chemical photography gradually died out, at least as a popular pastime.
Cette photo a été prise par un membre de ma famille, en 1979 ou à peu près, en utilisant un appareil photo reflex 35 mm classique. Comme c'était souvent le cas à ce moement-là, le film photographique couleur avait une sensibilité légèrement meilleure à la lumière rouge qu'au vert ou au bleu, et ça se voit sur l'épreuve finale. En plus, certaines alérations chimiques ont pu avoir lieu pendant toutes ces années, même s'il a été pris soin des clichés pour les stocker et les protéger. Ce sera le casp pour pratiquement toutesles photos de cette époque : quelques années plus tard, des films photo de meilleure qualité seront disponibles et la prédominance d'une couleur sera moins un problème vers la fin des années 90 ou début 2000 – alors même que la photographie argentique mourrera graduellement, au moins comme passe-temps populaire.
This image has been digitized by simply photographing the original using a modern mobile phone. This technique allows us to keep the original on its backing material, without the risk of damaging it if it were to be removed and unglued. Modern digital cameras have more than enough resolution to produce a nice reproduction; they compare well, in any case, to the flatbed scanners that used to be available some years back. On the other hand, photographing an original does require some careful thought about lighting the photo: the camera needs to be placed just about vertically in respect to the original, which means that lighting needs to be placed on the sides so not to create sharp reflections. No using the phone’s onboard flash for this purpose, so! Taking the picture on a flat table placed in front of a diffuse source of natural light –such as an open window on a slightly overcast day– may be a good technical solution.
Cette image a été numérisée en photographiant simplement l'original avec une téléphone mobile moderne. Cette technique nous permet de conserver l'original sur son matériau support, sans le risque de le détériorer en le retirant ou décollant. Les appareils-photo numériques modernes ont une résolution plus que suffisante pour donner une belle reproduction ; ils se mesurent bien, en tous cas, au scanners à plat qui étaient utilisés il y a quelques années. D'un autre côté, la photographie d'un original nécessitent de bie réfléchir à l'éclairage de la phto : l'appareil nécessite d'être placé bien verticalement au-dessus de l'original, ce qui entraîne que l'éclairage doit être placé surles côtés pour ne pas créer des réflexions ponctuelles. Pas d'utilsiation du flash intégré au mobile dans ce cas ! La bonne solution techinque serair de prendre la photo sur une table plate placée devant une source de lumière naturelle diffuse – telle qu'une fenêtre ouverte ou lors d'une journée légèrement couverte.
The first alteration I would like to do to this original is remove the black border, from the backing paper on which it was mounted. But I would like to retain the rounded corners, reminiscent of paper copies of that time and era. So, once the photo has been opened in Krita, I will not use the cropping tool. Instead, I will make the black border transparent. To do so, I selected the magic wand tool to select the border, and then hit the Suppress key on the keyboard. This tool will select contiguous regions of the same color. It does have a certain sensibility, which means that a narrow border around the image itself –which is gray in color, rather than proper black– will be conserved, as will some marks and splotches. These latter came from reflections off the black mounting paper. They can then be rubbed out individually, or selected using a selection tool and then erased. I like to start by selecting and erasing large areas using the rectangular selection tool, then going in with the circular eraser for the finer areas near the border. As usual, proceed with small, careful touches.
Now, let us analyze the colors, and lighting, in this image. As usual, a histogram will give us some information. As in the previous episode, newer versions of Krita have the histogram dock activation in menu “Tools”, “Dockers”, and then checkbox “Histogram”. In this image, we can see that there are no really dark pixels (far left of the histogram), nor any really light ones (far right). Our first task will be to balance lighting, using one of the tools Krita offers. The one “Filter”, “Adjust”, “Autocontrast”, will increase contrast at the expense of getting very sharp shadows across the subject’s face. This may be required to increase the contrast of a technical document, but is not desirable for a portrait or typical landscape. It is preferable, in this case, to use the tool at “Filter”, “Adjust”, “Levels”. From here, we can select the “Autolevels” button to have Krita calculate an optimized adjustment, which we can then go in and play with to get the exact effect we prefer. With a bit of practice, we can make contrast slightly higher than in the original image, but not excessive. This makes the subject stand out a bit from the background.
However, we still have an imbalance towards the red (shown next page, top middle), this slight tinge that comes from the film’s chemicals and which is still quite noticeable. Our histogram shows that we have made global color balance better across the range from dark to light, but there is still some excess red in the lighter part, to the right. Another of Krita’s tools is the color balance group, from the main menu “Filter”, “Adjust”, then “Color Balance”. This complete tool-set allows us to adjust color balance between red, green and blue individually for the lower (darker) tones, middle and higher (lighter) tone ranges.
By reducing the red in the lighter tones, the annoying reddish tinge goes away from the subject’s skin; the white part of the shirt now actually looks white, instead of pink. However, the sea and island lacked a tad of green to my eyes, so I put back some green into the midtones. This, however, gave the whole photo a greenish tinge to it, so I subtracted back some green out of the highlights. As a final adjustment to this picture, we need to correct some deformation that took place when it was digitized with a mobile phone; since the camera was not dead center on the image, it has suffered some small trapezoid deformation, specifically in the lower left corner. This is quite clear in the screenshots above where the transparent background is represented by a gray checkerboard: see how the lower edge of the image leans down from left to right.
To cure this, we can use the Transform tool in Krita. However, default options do not include trapezoid deformation, so we need to make the tool options docker visible through menu option “Settings”, “Dockers”, and check “Tool options”. We can then change from “Free Transform” to “Perspective” inside the tool options dock, and rectify the bottom edge of the image without touching the top. The final result is a photo that has more vibrant colors than its original, with a subject that is clearly distinct from the background, and is nicely squared around the edges.
If saving an image with rounded corners from Krita to a format that is accepted by most applications, do remember that the JPEG format cannot handle transparency. In these cases, the Portable Network Graphics (PNG) format is probably a good bet. The original photo in this month’s part of this series was transformed to a digital format by simply photographing it using a modern mobile phone. In some cases, however, we do not have a paper copy of the original. For instance, in the latter days of chemical photography, many photo developing shops were delivering CD copies of your photos, already digitized. These also can have some drawbacks, which we will review in the next part. Until then, take care!