---
title: "Loading and Saving Animated GIFs"
canonical: https://www.graphicsmill.com/docs/gm/loading-and-saving-animated-gifs.htm
product: "Graphics Mill"
---

# Loading and Saving Animated GIFs
 
The GIF file format is the most wide-spread graphic format that supports animation. Animated images saved in this format can be rendered by almost any modern image viewer. Graphics Mill allows working with GIF images as a whole or with each image frame separately. There are two main classes to deal with GIF files: [Codecs.GifReader](https://www.graphicsmill.com/docs/gm/T_Aurigma_GraphicsMill_Codecs_GifReader.htm.md) and [Codecs.GifWriter](https://www.graphicsmill.com/docs/gm/T_Aurigma_GraphicsMill_Codecs_GifWriter.htm.md). For more information about *format readers and writers* see the [Working with Files](https://www.graphicsmill.com/docs/gm/working-with-files.htm.md) topic.
 
This topic contains the following sections:
 
- reading GIF images, which describes how to load a GIF image and save its frames to separate image files
- writing GIF images, which demonstrates how to create a GIF image from a set of image files, and how to specify general GIF settings
- resizing GIF images, which examines how to shrink a GIF image

## Reading GIF Images
  
You can read a GIF image from a file or a stream by using the appropriate [GifReader constructor](https://www.graphicsmill.com/docs/gm/O_T_Aurigma_GraphicsMill_Codecs_GifReader_ctor.htm.md). After the image is opened use the [GifReader.Frames](https://www.graphicsmill.com/docs/gm/P_Aurigma_GraphicsMill_Codecs_GifReader_Frames.htm.md) property to get access to an image frame or to iterate through all frames in the image.
 
The following code reads a GIF image and saves its frames as separate PNG files:
 
```csharp
using (var reader = new GifReader(@"Images\slideshow.gif"))
{
    for (int i = 0; i < reader.Frames.Count; i++)
    {
        reader.Frames[i].GetBitmap().Save(@"Images\Output\GIF_frame_" + i.ToString() + ".png");
    }
}
```
 
## Writing GIF Images
  
To write a GIF image to a file or a stream use the appropriate [GifWriter constructor](https://www.graphicsmill.com/docs/gm/O_T_Aurigma_GraphicsMill_Codecs_GifWriter_ctor.htm.md). The [GifWriter properties](https://www.graphicsmill.com/docs/gm/Properties_T_Aurigma_GraphicsMill_Codecs_GifWriter.htm.md) allows specifying the general GIF image settings, such as playback count, image optimization, etc.
 
Any bitmap having GIF-supported pixel format can be a frame of a GIF image. You can check if the pixel format is supported either by using [the table](https://www.graphicsmill.com/docs/gm/supported-file-formats.htm.md) or via the [IsPixelFormatSupported(PixelFormat)](https://www.graphicsmill.com/docs/gm/M_Aurigma_GraphicsMill_PipelineElement_IsPixelFormatSupported_1_3e209c07.htm.md) method. To add a frame to the writer, run a pipeline by calling the [Pipeline.Run](https://www.graphicsmill.com/docs/gm/O_T_Aurigma_GraphicsMill_Pipeline_Run.htm.md) method. If you are not familiar with pipelines, read the [Understanding Image Processing Approaches in Graphics Mill](https://www.graphicsmill.com/docs/gm/understanding-image-processing-approaches-in-graphics-mill.htm.md) topic.
 
The following code creates an animated GIF image from separate PNG files:
 
```csharp
int framesCount = 4;

using (var writer = new GifWriter(@"Images\slideshow.gif"))
{
    writer.FrameOptions.Delay = 100;

    for (int i = 0; i < framesCount; i++)
    {
        using (var reader = ImageReader.Create(@"Images\GIF_frame_" + i.ToString() + ".png"))
        {
            Pipeline.Run(reader + writer);
        }
    }
}
```
 
## Resizing GIF Images
  
To resize an animated GIF file you should resize each of its frames separately. So you need to perform the following steps:
 
1. Copy general setting of the GIF file.
2. Iterate through all frames of the image. For each frame perform the following steps:
    1. Copy frame settings to a new frame using the [GifWriter.FrameOptions](https://www.graphicsmill.com/docs/gm/P_Aurigma_GraphicsMill_Codecs_GifWriter_FrameOptions.htm.md) property.
    2. Get the bitmap of the frame.
    3. Preserve the original palette and pixel format.
    4. Resize the bitmap in a high quality mode to avoid color and transparency loss.
    5. Convert the bitmap back to the indexed format keeping the transparency.
    6. Add the frame to the writer by running a pipeline. If you are not familiar with pipelines, read the [Understanding Image Processing Approaches in Graphics Mill](https://www.graphicsmill.com/docs/gm/understanding-image-processing-approaches-in-graphics-mill.htm.md) topic.

The following code resizes an input GIF image to half of original width and height.
 
```csharp
using (var reader = new GifReader(@"Images\slideshow.gif"))
using (var writer = new GifWriter(@"Images\Output\slideshow1.gif"))
{
    //Copy general properties of the source file
    writer.BackgroundIndex = reader.BackgroundEntryIndex;
    writer.Palette = reader.Palette;
    writer.PlaybackCount = reader.PlaybackCount;

    for (int i = 0; i < reader.Frames.Count; i++)
    {
        //Read a frame
        using (var frame = reader.Frames[i])
        using (var bitmap = frame.GetBitmap())
        {
            //Preserve the original palette
            ColorPalette palette = bitmap.Palette;
            //Preserve the original pixel format
            PixelFormat pixelFormat = bitmap.PixelFormat;

            //Convert the bitmap to a non-indexed format
            bitmap.ColorManagement.Convert(ColorSpace.Rgb, true, false);

            //Resize the bitmap in a high quality mode
            bitmap.Transforms.Resize(frame.Width / 2, frame.Height / 2, ResizeInterpolationMode.High);

            //Return to the indexed format
            bitmap.Palette = palette;
            bitmap.ColorManagement.Convert(pixelFormat);

            //Copy frame delay
            writer.FrameOptions.Delay = frame.Delay;

            //Add the frame
            Pipeline.Run(bitmap + writer);
        }
    }
}
```
 
## See Also
  
### Reference
 
- [Codecs.GifReader Class](https://www.graphicsmill.com/docs/gm/T_Aurigma_GraphicsMill_Codecs_GifReader.htm.md)
- [GifReader.Frames Property](https://www.graphicsmill.com/docs/gm/P_Aurigma_GraphicsMill_Codecs_GifReader_Frames.htm.md)
- [Codecs.GifWriter Class](https://www.graphicsmill.com/docs/gm/T_Aurigma_GraphicsMill_Codecs_GifWriter.htm.md)
- [GifWriter.FrameOptions Property](https://www.graphicsmill.com/docs/gm/P_Aurigma_GraphicsMill_Codecs_GifWriter_FrameOptions.htm.md)

### Manual
 
- [Working with Files](https://www.graphicsmill.com/docs/gm/working-with-files.htm.md)
- [Supported File Formats](https://www.graphicsmill.com/docs/gm/supported-file-formats.htm.md)