在绘制的压缩图像上避免性能降级

在绘制的压缩图像上避免性能降级

有时候，您可能希望在压缩图像上执行非常复杂的图形操作。当 Aspose.PSD 需要在运行时压缩和解压图像时，性能可能会下降。在压缩图像上绘制也可能会导致性能损失。

解决方案

为了避免性能下降，我们建议在执行图形操作之前将图像转换为未压缩或原始格式。

使用文件路径

在接下来的示例中，一个 PSD 图像被转换为原始格式（无压缩）并保存到磁盘。然后在执行图形操作之前重新加载未压缩的图像。相同的技术适用于 BMP 和 GIF 文件。

        String dataDir = Utils.getDataDir(UncompressedImageUsingFile.class) + "PSD/";

        // Load a PSD file as an image and cast it into PsdImage
        try (PsdImage psdImage = (PsdImage) Image.load(dataDir + "layers.psd")) {

            PsdOptions saveOptions = new PsdOptions();
            saveOptions.setCompressionMethod(CompressionMethod.Raw);
            psdImage.save(dataDir + "uncompressed_out.psd", saveOptions);

// Now reopen the newly created image.
            PsdImage img = (PsdImage) Image.load(dataDir + "uncompressed_out.psd");

            Graphics graphics = new Graphics(img);
            // Perform graphics operations.
        }

使用流对象

下面的代码片段展示了如何将 PSD 图像转换为原始格式（无压缩）并使用 Stream 保存到磁盘。

        String dataDir = Utils.getDataDir(UncompressedImageStreamObject.class) + "PSD/";

        ByteArrayOutputStream ms = new ByteArrayOutputStream();

// Load a PSD file as an image and cast it into PsdImage
        try (PsdImage psdImage = (PsdImage) Image.load(dataDir + "layers.psd")) {

            PsdOptions saveOptions = new PsdOptions();
            saveOptions.setCompressionMethod(CompressionMethod.Raw);
            psdImage.save(ms, saveOptions);

// Now reopen the newly created image. But first seek to the beginning of stream since after saving seek is at the end now.

            ms.reset();

            PsdImage img = (PsdImage) Image.load(new ByteArrayInputStream(ms.toByteArray()));
            Graphics graphics = new Graphics(psdImage);
            // Perform graphics operations.
        }