LayerMaskData.MaskRectangle

LayerMaskData.MaskRectangle property

Gets or sets the mask Rectangle of the layer mask in the PSD file. It takes left, right, top and bottom properties and creates Rectangle

public Rectangle MaskRectangle { get; set; }

Property Value

The mask rectangle.

Examples

This example shows how to get, update, remove and add raster layer masks in the Adobe® Photoshop® file programmatically.

[C#]

void AssertAreEqual(object actual, object expected)
{
    if (!object.Equals(actual, expected))
    {
        throw new FormatException(
            string.Format("Actual value {0} are not equal to expected {1}.", actual, expected));
    }
}

// Gets the int value converted to big-endian bytes order.
byte[] GetBigEndianBytesInt32(int value)
{
    byte[] bytes = new byte[4];
    bytes[0] = (byte)((value >> 24) & 0x000000FF);
    bytes[1] = (byte)((value >> 16) & 0x000000FF);
    bytes[2] = (byte)((value >> 8) & 0x000000FF);
    bytes[3] = (byte)value;
    return bytes;
}

// Gets the value converted from the big endian to Int32.
int FromBigEndianToInt32(byte[] bytes, int index)
{
    if (bytes == null)
    {
        throw new ArgumentNullException("bytes");
    }

    if (index < 0 || index + 4 > bytes.Length)
    {
        throw new ArgumentOutOfRangeException("index", "The index falls outside the bytes array.");
    }

    return (bytes[index] << 24) | (bytes[index + 1] << 16) | (bytes[index + 2] << 8) | bytes[index + 3];
}

// Gets a raster mask from the layer of a PSD image and saves it to a file
void SaveRasterMask(string maskFilePath, Layer layer)
{
    LayerMaskDataShort maskData = (LayerMaskDataShort)layer.LayerMaskData;

    using (var container = FileStreamContainer.CreateFileStream(maskFilePath, false))
    {
        container.Write(GetBigEndianBytesInt32(maskData.Top));
        container.Write(GetBigEndianBytesInt32(maskData.Left));
        container.Write(GetBigEndianBytesInt32(maskData.Bottom));
        container.Write(GetBigEndianBytesInt32(maskData.Right));
        container.WriteByte(maskData.DefaultColor);
        container.WriteByte((byte)maskData.Flags);
        container.Write(GetBigEndianBytesInt32(maskData.ImageData.Length));
        container.Write(maskData.ImageData, 0, maskData.ImageData.Length);
    }
}

// Adds a raster mask from the file to the layer and saves it the PSD format image
void AddRasterMask(Layer layer, string maskSourcePath)
{
    var maskData = new LayerMaskDataShort();
    using (FileStreamContainer container = FileStreamContainer.OpenFileStream(maskSourcePath))
    {
        byte[] bytes = new byte[22];
        AssertAreEqual(container.Read(bytes), 22);
        maskData.Top = FromBigEndianToInt32(bytes, 0);
        maskData.Left = FromBigEndianToInt32(bytes, 4);
        maskData.Bottom = FromBigEndianToInt32(bytes, 8);
        maskData.Right = FromBigEndianToInt32(bytes, 12);
        maskData.DefaultColor = bytes[16];
        maskData.Flags = (LayerMaskFlags)bytes[17];
        int imageDataLength = FromBigEndianToInt32(bytes, 18);
        byte[] data = new byte[imageDataLength];
        AssertAreEqual(maskData.MaskRectangle.Width * maskData.MaskRectangle.Height, imageDataLength);
        AssertAreEqual(container.Read(data), imageDataLength);
        maskData.ImageData = data;
    }

    // Just adding LayerMaskData is not enough for correct saving because channels are not updated;
    // layer.LayerMaskData = mask; // This does not add the mask channel

    // Add (or update) the mask
    layer.AddLayerMask(maskData); // But this adds / updates both the mask and channels!
}

// This example shows how to get, update, remove and add raster layer masks in the Adobe® Photoshop® file programmatically.
var pngOptions = new PngOptions() { ColorType = PngColorType.TruecolorWithAlpha };
var sourceFilePath = "FourWithMasks.psd";
using (PsdImage image = (PsdImage)Image.Load(sourceFilePath))
{
    Layer layer = image.Layers[2];

    // Get a raster mask from the layer and save it to a file
    SaveRasterMask("FourWithMasks2.msk", layer);

    // Change the layer mask (invert) and save the image
    var mask = layer.LayerMaskData;
    byte[] maskData = mask.ImageData;
    for (int i = 0; i < maskData.Length; i++)
    {
        maskData[i] = (byte)~maskData[i];
    }

    // Just changing LayerMaskData is enough to effect rendering
    image.Save("FourWithMasksUpdated2.png", pngOptions);

    // But just changing LayerMaskData is not enough for correct saving because channels are not updated;
    layer.LayerMaskData = mask; // This does not work either
    layer.AddLayerMask(mask); // But this updates both the mask and channels!
    image.Save("FourWithMasksUpdated2.psd");

    // Remove a raster mask from the layer and save the image
    layer.LayerMaskData = null; // Just removing LayerMaskData is enough to effect rendering but not for saving to PSD format
    image.Save("FourWithMasksRemoved2.png", pngOptions);

    layer.AddLayerMask(null); // But this removes both the mask and the mask channel!
    image.Save("FourWithMasksRemoved2.psd");

    // Add a raster mask from the file to the layer and save the image
    AddRasterMask(layer, "raster.msk");
    image.Save("FourWithMasksAdded2.png", pngOptions);
    image.Save("FourWithMasksAdded2.psd");
}

See Also

LayerMaskData.Left LayerMaskData.Right