Commons:Các bước đầu tiên/Chất lượng và miêu tả
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This page gives a quick guide to making high quality contributions to Wikimedia.
Làm thế nào để các tác phẩm tải lên được hoàn hảo nhất
Hình ảnh
Nói chung, chất lượng và độ phân giải hình ảnh nên ở mức cao nhất có thể để phục vụ nhiều mục đích, như các bản in chất lượng cao chẳng hạn. MediaWiki, phần mềm wiki chạy trên máy chủ của chúng tôi và được cài đặt trên tất cả các dự án Wikimedia, có thể co dãn hình ảnh ở hầu hết các định dạng ngay trên web khi cần và có không gian lưu trữ không giới hạn, do đó không nên để những lo lắng về thời gian tải xuống và kích thước ảnh hưởng đến chất lượng hình ảnh tải lên của bạn.
Kích thước và co dãn hình ảnh
Tính đến ngày 1 tháng 5 năm 2013, phần mềm MediaWiki không thể làm việc với các hình ảnh định dạng GIF và TIFF có độ phân giải chính xác lớn hơn 50 megapixel — tuy nhiên các hình ảnh ở độ phân giải này vẫn được chấp nhận. Với các ảnh GIF động, bạn phải tự nhân số khung hình với độ phân giải của mỗi khung hình. Các bản thu nhỏ của ảnh PNG được tự động tạo ra nếu ảnh gốc có độ phân giải nhỏ hơn khoảng 2.500 megapixel (2.500.000.000 pixel) — tương đương ảnh vuông (1.00:1) có kích thước 50.000×50.000 pixel, ảnh có tỷ lệ khung hình 4:3 (1.33:1) với độ phân giải 57.732×43.299 pixel, ảnh có tỷ lệ vàng (1.62:1) với độ phân giải &num5 pixel, hoặc ảnh có tỷ lệ 16:9 (1.78:1) với độ phân giải 66.656×37.494 pixel.
Giới hạn dung lượng tập tin được tăng lên 100 MB vào cuối năm 2008. Với các công cụ tải tập tin dung lượng lớn, ví dụ như trong trình tải lên Upload Wizard (yêu cầu một trình duyệt web hiện đại), bạn có thể tải các tập tin với dung lượng lên đến 500 MB.
Filetypes and naming
Only certain file types are allowed in Wikimedia Commons. If you try to upload a different file type, you'll receive an error message.
The destination filename you give will be the title of the image description page; you may want to follow naming conventions. If you modify an image of others, please upload it under a different filename and add links to and from the original.
Format guidance
Different formats should be used for different types of images. JPEG works well with images with lots of details like photographs. A diagram, however, suffers compression artifacts when saved as JPEG and, like GIF and PNG, cannot be scaled without loss of quality.
SVG works well with charts, diagrams, and other images where there are few details. (However, if you can't get the diagram in vector form, PNG is still better than JPEG.) SVG can be edited easily and scaled with no loss of quality, but its use in photographs, for instance, is impractical.
GIF is cumbersome for use with the server software and due to inherent restrictions in the format, use of GIF should be restricted to animated images only. For further information on image formats, format conversion, and other format recommendations, see Commons:Preparing images for upload.
- Photographs: For photographs, use JPEG (file extension
.jpgor.jpeg). While TIFF offers higher quality, these files tend to be rather large, especially when they are not compressed. PNG uses a lossless compression (that is: no information is removed) and is thus theoretically better for photographs, but it too produces excessively large file sizes for high-resolution photographs.
PNG should be reserved for images that require high quality and/or that it can more easily compress, such as computer screenshots (or diagrams only available in raster form). Do not save JPEG images as "progressive".[1] Please optimize JPEG images (this reduces size at no cost to decoding).[clarification needed]
- Animated images: For animated images, use GIF (file extension
.gif).
- Diagrams: For diagrams, charts, etc., SVG (Scalable Vector Graphics, file extension
.svg) is the preferred type (or, if you can't get vectors, use PNG).
Audio and video
Supported sound types are MIDI (file extension: .mid) and Ogg Vorbis (.ogg) and for video files WebM (.webm) or Ogg Theora (also .ogg or .ogv). Other widely used sound file formats like WMA and video formats like WMV are not allowed at Wikimedia Commons due to patent issues.
Like images, quality of sound and video files should not be too low. The upper limit for file sizes is 100 megabytes, so choose quality depending on the duration of your media file. For information on format conversion and encoding, see Commons:Software.
Good file descriptions
A good file description provides complete information about the file, including legally required information such as its copyright status and source, as well as descriptive information about what it shows and how it was made. Without this information making judgements about the provenance of an image is very difficult and its value is much reduced to editors and researchers.
To assist you in creating such a description, there is a standardized template for images. Additionally, this template is rendered in a typographically sound way and provides Machine-readable data which in turn is used for creating information for reusers. It is therefore highly recommended to use the template.
N.B. there are special templates for works of art {{Artwork}} and books {{Book}} that should be used in place of (or, in the case of some photographs, in addition to) the template {{Information}} shown hereafter, see the relevant template documentation pages for more information.
Just copy the code below, paste it into the "Summary" field during upload and fill in the blanks:
{{Information
|Description=
|Date=
|Source=
|Author=
|Permission=
|Other versions=
}}
- The fields are used the following way
If you can't fill in everything, leave them blank, as the template won't work as advertised otherwise (internationalization, categorization).
- Description
Description of the content. What do you see, hear, or otherwise perceive? If it's an artwork, please provide brief historical background. In case of scientific data, a brief scientific abstract of the file. If you have detailed information about an image, for example the name of the species or the size of the object, please add it. Especially with mineral images, including the size is helpful. Stating where a photograph was taken never hurts and is often essential, as for almost any non-astronomical photograph taken outdoors, among others.
Descriptions can be in any language, but it is always a good idea to include an English description as well. If you can write in more than one language, consider adding the description in all of them. See this note about creating wikilinks.
- You should use templates to declare language(s) of the description. It can look like:
{{Information
|Description=
{{cs|1=Nějaký český popisek.}}
{{en|1=Some description in English.}}
…
|Source=…
- Source
- Use the template {{Own}}, if you created that file yourself. Otherwise please supply a
- Link to a website, with a direct link to the page embedding the file and a direct link to the file
- Catalog number
- Name of institution
- Book source
- Etc.
- See also Commons:Essential information: Source.
- Date
- Date of creation (or date of release), preferably in ISO 8601 format, such as
2006-01-15for 15 January 2006.
- Author
- Author(s) of the file. If you don't know any individual, use the name of the institution(s) which released it. In case of self-made work, put your real name (or pseudonym), and link to your username such as "
[[User:JQPublic|John Q. Public]]", which will be rendered as "John Q. Public". Alternatively, link to your username in parentheses, such as "John Q. Public ([[User:JQPublic|JQPublic]])" or "John Q. Public ({{U|JQPublic}})", which will be rendered as "John Q. Public (JQPublic)".
- Permission
- Note: You still need to tag the image in any case with the appropriate license template (aka Copyright tag)!
- Supply a short quote of the permission the copyright owner of the file gave you. In case of a general permission (e. g. US Public Domain or free content licenses) supply a short link to that legal disclaimer or an according hint. If you are the copyright owner, but not the author, please indicate this here; if you are the author and copyright-holder, leave it blank and use {{Own}} as the source and make sure, you wrap your Copyright tag in {{Self}} (e.g. {{self|Cc-by-sa-3.0}}).
- Other versions of this file
- If there are other version of this file within Wikimedia Commons (for example a black and white version of a color image, or a cropped or uncropped version) use this field to link to these versions with a wikilink.
Note: For many media it is desirable to use a geocoding template in addition to the Information template. Please also read First steps/Sorting.
Upload summary
When you are uploading a file, the upload form gives you a place for a summary. Everything you enter will appear permanently on the image description page, in the "File history" section.
If you are uploading the first version of a file (there is not already a file with the title you selected), then your upload summary will also be copied to the image description page. It is common in this case to provide complete information in the summary, as detailed under Good file descriptions hereinbefore.
If you are uploading a new version of a file, it is important to specify in as much detail as possible how you changed the file. This information is important because it can be difficult for others to tell the difference between two files. For example, for an image, you could say:
- Cropped 25 pixels off the top, brightened with Photoshop, saved at 95% quality
Ideally, one will provide a command line or exact list of commands that reproduces the changes, though this is by no means necessary, and often not possible.
Notes
- ↑ Progressive images break the thumbnailer, because the whole image must be rendered, thus exhausting memory. See archived discussion and example.
Further reading
Wikimedia Commons pages:
Wikipedia page:
MediaWiki handbook: