ياداشت

When you opened an image in older GIMP releases, let's say a JPG or PNG, the image kept its format and was saved in the same format by using Save. Since GIMP 2.8, all images are 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.

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 allows you to export the images you create in a wide variety of formats. It is important to realize that the only format capable of saving all of the information in an image, including layers, transparency, etc., is GIMP's native XCF format. Every other format preserves some image properties and loses others. It is up to you to understand the capabilities of the format you choose.

Exporting an image does not modify the image itself, so you do not lose anything by exporting. See Export file.

ياداشت

When you close an image (possibly by quitting GIMP), you are warned if the image is "dirty"; that is, if it has been changed without subsequently being saved (an asterisk is in front of the image name). شكل 6.1. Closing warning 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.

1.2.1. Export Image as GIF

شكل 6.2. The GIF Export dialog

	هشدار
	The GIF file format does not support some basic image properties such as print resolution. If you care for these properties, use a different file format like PNG.

GIF Options

Interlace

Checking interlace allows an image on a web page to be progressively displayed as it is downloaded. Progressive image display is useful with slow connection speeds, because you can stop an image that is of no interest; interlace is of less use today with our faster connection speeds.

GIF comment

GIF comments support only 7-bit ASCII characters. If you use a character outside the 7-bit ASCII set, GIMP will export the image without a comment, and then inform you that the comment was not saved.

Animated GIF Options

Loop forever

When this option is checked, the animation will play repeatedly until you stop it.

Delay between frames where unspecified

You can set the delay, in milliseconds, between frames if it has not been set before. In this case, you can modify every delay in the Layer Dialog.

Frame disposal where unspecified

If this has not been set before, you can set how frames will be superimposed. You can select among three options :

• I don't care: you can use this option if all your layers are opaque. Layers will overwrite what is beneath.

• Cumulative Layers (combine): previous frames will not be deleted when a new one is displayed.

• One frame per layer (replace): previous frames will be deleted before displaying a new frame.

Use delay entered above for all frames

Self-explanatory.

Use disposal entered above for all frames

Self-explanatory.

1.2.2. Export Image as HEIF/HEIC

HEIF stands for High Efficiency Image File Format. Also known as HEIC High Efficiency Image Coding.

Twice as much information can be stored in a HEIF image as in a JPEG image of the same size, resulting in a better quality. As of October 2019, no browser supports HEIF natively.

More information in Wikipedia.

شكل 6.3. The HEIF/HEIC Export dialog

These options are self-explanatory.

1.2.3. Export Image as JPEG

JPEG files usually have an extension .jpg, .JPG, or .jpeg. It is a very widely used format, because it compresses images very efficiently, while minimizing the loss of image quality. No other format comes close to achieving the same level of compression. It does not, however, support transparency or multiple layers.

شكل 6.4. The JPEG Export dialog

The JPEG algorithm is quite complex, and involves a bewildering number of options, whose meaning is beyond the scope of this documentation. Unless you are a JPEG expert, the Quality parameter is probably the only one you will need to adjust.