FAQ

Download of pictures

1 - How to download single image via your site ?


The easiest way is to use the H5AI file explorer and its integrated download function.
Once your image is found, click on it to open the preview.

When the image preview is open, click on the small arrow at the bottom right:

The image opens in original quality in a new tab or window, you can save it by right-clicking then “save image as …”
The image may also be downloaded automatically.

2 - How to download all images from a mission via your site ?(recommended)


You have to use the method explained in point 5.

3 - How do I download all images from a mission via Firefox DownThemAll extension ? (not recommended)


1°) Download and install DownThemAll for Firefox
2°) Go to the image bank via the Minigal Nano galery
3°) Go to the folder you want to download (warning, DownThemAll will only download the images in this folder, but not the subfolders)
4°) Click the DownThemAll button in the top right corner of Firefox

5°) In the new window that opens, all images that interest us should be automatically checked. If this is not the case it is PNG images, you must click on “Filters” then check “Images (jpg, png, …)”. Be sure to choose the download path in the “Save files to:” field. Finally, click “Start”.

6°) All you have to do is wait for the download to complete, your images will be available in the location specified above.

TIP: To download multiple missions / batches of one moves, simply open each mission in a new Firefox tab (1 tab per mission) and then click on the arrow next to the DownThemAll button, then click on “DownThemAll! (All tabs) “and follow the instructions in step 5.


4 - How to download all images from a mission using the Jdownloader software? (not recommended)


1°) Download and install Jdownloader
2°) Go to the image bank via Minigal Nano galery
3°) Go to the folder you want to download (attention, Jdownloader will only upload the images in this folder, but not the subfolders)
4 °) Copy the address of the folder in which you are located

5 °) Open the Jdownloader program and click on the “Link collector”
6 °) Right-click in the main area of the software (white area, empty, containing the columns “Name, URL, Path, …”)
7 °) Click on “Add Links”

8 °) In the new window that has just opened, paste the address you copied in step 4 into the first field
9 °) In the second field, click on “Edit Path” to change the location where the images will be downloaded, if necessary.
10 °) Click on “Continue”

11 °) The window below will open and links will appear in the background, wait for this window to disappear.

12 °) Click on the “Play” button at the top left of the software, as on the capture below. You will be automatically “redirected” to the “Download” tab, you just have to wait until the download is complete. You will find your images in the folder specified in point 9.

TIP: To download several missions / batches of a shots, simply copy / paste the links of each missions in the field indicated in step 8, one below the other.

5 - How to download all the image bank via your site?

We provide you with a specially created sFTP account for bulk downloading of the image bank. Here’s how:

1°) Download and install FileZilla

2°) Open FileZilla

3°) Click on “Display” then check “Quick connection bar” if it is not already the case

4°) Fill in the fields like this:
_Hôte: 163.172.216.112
_Login: invité
_Password: invité
_Port: 22

Then click on “Quick Connect”

5 °) You now have access to the “Universe” folder and all its contents. You can navigate in the tree and download what you want by dragging and dropping from the right window (our server) to the left window (your PC)

6 - How to download all the image bank via a software?

I advise you to use the sFTP account provided in point 5. Otherwise, you will probably need to use a combination of software : Xenu to retrieve URLs, Notepad ++ to sort them and jdownloader to download them.

Quality of pictures

7 - What is the quality of the images in your database?

In the image bank, the photographs are in their original resolutions as they were on the official site where I retrieved them, HOWEVER, they have all been processed with two image optimization software: png-out for The images in .png format and jpegtran for the .jpg format.
Here are the two command lines used:

>
for %%i in (*.jpg) do "C:\Program Files\Image
Optimization\jpegtran.exe" -optimize -progressive -copy all "%%i"
"%~1\OptimizedJPEGS\%%i"

> for %%i in (*.png) do "C:\Program Files\Image Optimization\pngout.exe" "%%i"

More information in the section “Recovering and processing images”

8 - What is the quality of the images on the homepage?

On the homepage, the images are all resized to make 3000 pixels wide and undergo a strong compression processing (80% of the original quality), all using the PhotoFiltre software.

9 - What is the quality of images in the blog ?

Images on the blog are usually reduced and compressed. However, when it comes to an article about adding a batch to the image bank, then the images displayed at the end of the article are in their original resolutions (but compressed anyway).

10 - Do images in the database contain only real photographs?

Yes and no. In the majority of cases, these are “100% authentic” photographs, but you can find what are called false color photographs but also, in a much smaller proportion, computer generated images from data recovered in general by a probe such as measurements or relief mapping. I advise you to read this article about false color photographs. It should also be known that often the photos are constructed from several photographic sources (telescope images, images of the observatories on the ground, etc.)

Image Recovery and Processing

11 - How do you retrieve all these images? Do you download them one by one?

Luckily, no! We use different batch downloading and content upgrading software to recover these images, including the Firefox extension “DownThemAll”, the “Jdownloader” and “Xenu” software.

12 - Where do you find all these images?

We retrieve these images from the various official sites of the space agencies, you can have more details on the page “Image bank“, part “Sources “

13 - Can you be more precise about the processing of the images mentioned in point 7 ?

For the .png image format, here are the technical details:

“The main function of PNGOUT is to reduce the size of the image data contained in the IDAT chunk, which is compressed using the DEFLATE algorithm, DEFLATE algorithms can vary in speed and compression ratio, With higher compression rates typically involving a lower speed Ken Silverman wrote a DEFLATE compressor for PNGOUT which is slower than most graphics software, but produces smaller files. Depth, color and pallet, if any. ”

For the .jpg format, here are the technical details:

• The -optimize parameter optimizes Huffman tables
• The -progressive parameter converts JPEG to progressive, concretely a progressive JPEG loaded at only 20% will completely cover the area it is supposed to occupy (and will gradually refine), while the JPEG baseline will only display 20% Of its surface area.
See this article for more details.
The -copy all parameter tells JPEGTran to keep all EXIF data of the image (among others).

14 - Are all the pictures of a mission presented or do you make a sorting?

Overall, I try to put as many pictures as possible on a mission, but two things are taken into account: I sort by removing photos where there are no celestial objects, missed photos, and so on. Secondly, take into account the colossal number of photos proposed by the space agencies, for example, take a look at the number of photos available for SDO, at the rate of several images every 15 minutes since April 2010 …

Images informations

15 - Can I see the EXIF and IPTC images?

I never erase the EXIF or IPTC data, but it may happen that an image has none. You can view this data via this navigation mode. Once the image is displayed, click on “information” at the bottom of the page, the EXIF and IPTC data appear on the left of the page.

About the site / author

16 - How much do you manage this site?

At the moment, I am the only one who managed the entire site, but the server was installed by two people who continue to help me manage it.

17 - How is this site hosted?

This site is hosted on a dedicated server, a Dedibox SC 2016. The hosting provider is Online.net
Technical details :

_Intel® C2350 Processor (Avoton) 2C / 2T @ 1.7 Ghz
_ Memory 4 GB DDR3
_ Storage 1 TB SATA

18 - How much does this site cost?

Cost of accommodation HT: 8,99 € / month
Cost of accommodation: 10,79 € / month

Cost of the domain name HT: 7,99 € / ans
Cost of the domain TTC: 9,59 € / year

Total cost (excluding VAT) per month: ~ 9,66 €
Total cost (including tax) per month: ~ 11,59 €

The site is 100% financed by my personal means. No ads, no donations, etc.

19 - You work in the field of space or scientific research?

Absolutely not, I am a computer support technician in a hotline. I do not have a telescope and never manipulated one. I just find it amazing what is all around us. That said, I am very interested in space and astronomy, whether there is a link with the photographs or not. All this to say that I do not have a pro, so you may find errors in my articles (because I would have misunderstood a complex scientific article, for example). If you find errors, you are cordially invited to report them to me!