图像压缩错误的颜色

Question

我使用java代码压缩图像。有时我会得到错误颜色的图像。我不明白为什么它的行为是不一致的。

从网址下载的图片

 public void imageDownload() {

            String key = (String) map.get("key");
            String url = (String) map.get("url");
    **String imagePath = java.util.UUID.randomUUID() + ".jpg";
    String compressedImage = Constant.COMPRESSED + imagePath;**

        try {
            URL url = new URL(url);
            InputStream is = url.openStream();
            // Stream to the destionation file
            FileOutputStream fos = new FileOutputStream(imagePath);

            // Read bytes from URL to the local file
            byte[] buffer = new byte[4096];
            int bytesRead = 0;
            while ((bytesRead = is.read(buffer)) != -1)
                fos.write(buffer, 0, bytesRead);

            // Close destination stream
            fos.close();
            // Close URL stream
            is.close();

            compressFile(imagePath, compressedImage, key);
        } catch (Exception exception) {
            log.debug("Exception occured while downloading images..." + exception.getLocalizedMessage());
        }

    }

}

图片压缩代码

private void compressFile(final String inputFilePath, final String outputFilePath,final String fileKey) {

        log.debug("Image file name::" + outputFilePath);
        log.debug("Image key is::" + fileKey);

        final String outputImagePath = tempFilePath + outputFilePath;

        final File inputFile = new File(inputFilePath);

        float quality = FileUpload.getQuality(inputFile);

        log.debug("Image size for url is::" + inputFile.length() + "quality constent::" + quality);
        final File outputFile = new File(outputImagePath);

        boolean s3Uploaded = true;
        if (quality != 0.0f) {
            final boolean isCompressed = FileUpload.fileCompress(inputFile, outputFile, quality);
        }
    }

压缩代码

public static boolean  fileCompress(File inputFilePath, File outputFilePath, float quality) {

        log.debug("File compress with path::" + inputFilePath + "output file path" + outputFilePath);

        boolean isCompressed = false;

        OutputStream os = null;
        ImageOutputStream ios = null;
        ImageWriter writer = null;
        try {
            BufferedImage image = ImageIO.read(inputFilePath);

            os = new FileOutputStream(outputFilePath);
            Iterator<ImageWriter> writers = ImageIO.getImageWritersByFormatName("jpg");
            writer = (ImageWriter) writers.next();
            ios = ImageIO.createImageOutputStream(os);
            writer.setOutput(ios);

            ImageWriteParam param = writer.getDefaultWriteParam();

            param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
            param.setCompressionQuality(quality);
            writer.write(null, new IIOImage(image, null, null), param);
            os.close();
            ios.close();
            writer.dispose();
            isCompressed = true;
        } catch (Exception exception) {
            log.error("File could not compress due to " + exception.getCause());
            isCompressed= false;
        }
        return isCompressed;
    }

获得质量参数

public static float getQuality(File input) {
        long size = input.length();
        log.debug("getting quality constant on the basis of image size: " + size);
        if (size > 768000) {
            return 0.3f;
        }
        if (size > 512000 && size <= 768000) {
            return 0.6f;
        }
        if (size > 256000 && size <= 512000) {
            return 0.7f;
        }
        if (size > 51200) {
            return 0.9f;
        }
        return 0.0f;
    }

被破坏的图像（图像大小在压缩之前 - 84616）

由于