第 6 章 从 GIMP 中获取图像

目录

1. 文件
1.1. 保存/导出图像
1.2. 文件格式
2. 为网络准备图像
2.1. 具有最佳尺寸/质量比的图像
2.2. 进一步缩小文件大小
2.3. 保存带有透明度的图像

1. 文件

GIMP is capable of reading and writing a large variety of graphics file formats. With the exception of GIMP's native XCF file format, file handling is done by plug-ins. This makes it relatively easy to extend GIMP to support new file types when the need arises.

1.1. 保存/导出图像

[注意] 注意

When you open an image, let's say in JPG or PNG file format, it is imported into GIMP's own XCF format, as a new project.

For example, a sunflower.png image will be loaded as *[sunflower] (imported)-1.0 (indexed color, 1 layer). The leading asterisk indicates that this file has been changed. This image can be saved as sunflower.xcf by using the Save command. If you need your image in another format, you should use the Export command.

When you are finished working with an image, you will save the results. In fact, it is often a good idea to save at intermediate stages too. GIMP is a pretty robust program, but on rare occasions crashes have happened.

GIMP's native format XCF is special. It is the only format that can store everything about an image (with the exception of undo information). This is the reason that saving can only be done in this format. It makes the XCF format especially suited for storing intermediate results, and for saving images to be re-opened later in GIMP.

XCF files are not readable by most other programs that display images. Once you have finished editing your image, you can export it to the format of your choice. GIMP supports a wide range of formats. Most file formats that can be imported, can also be used for exporting.

1.2. 文件格式

There are several commands for saving and exporting images. They are listed in the section covering the File Menu. More information on how to use them can be found there.

GIMP 允许您以多种格式导出您创建的图像。重要的是要认识到,能够保存图像中所有信息(包括图层、透明度等)的唯一格式是 GIMP 的原生 XCF 格式。其他所有格式都会保留一些图像属性并丢失其他图像属性。取决于您了解您选择的格式的功能。

导出图像不会修改图像本身,因此导出不会丢失任何内容。请参阅导出文件

[注意] 注意

当您关闭图像(可能是通过退出 GIMP)时,如果图像是“脏的”,您会收到警告;也就是说,如果它在进行了更改,没有随后保存的情况下(星号在图像名称前面)。

图 6.1. 关闭警告

关闭警告

Saving an image in GIMP's native format XCF will cause the image to be considered "not dirty". On the contrary, exporting an image will not change it to "not dirty", because GIMP can't know for sure that no image information will be lost.