将图像保存在 django 的临时文件中

Question

我对 python 和 django 非常陌生。我使用 django 开发了一个项目。这里所有的图像都带有水印。我使用以下代码为所有图像添加了水印......

from PIL import Image
    def image_watermark(request,image_id):
        photo = Photo.objects.get(pk=image_id)
        watermark = Image.open('{0}/{1}'.format(settings.MEDIA_ROOT,'wmark.png'))
        img = Image.open(photo.photo.file)

        img.paste(watermark,(img.size[0]-watermark.size[0],img.size[1]- watermark.size[1]),watermark)

        img.save('{0}/{1}'.format(settings.MEDIA_ROOT,photo.photo.name), quality=80)


        wrapper = FileWrapper(open(photo.photo.url, 'rb'))
        response = StreamingHttpResponse(wrapper, 'image/jpeg')
        response['Content-Length'] = os.path.getsize(photo.photo.url)
        response['Content-Disposition'] = 'attachment; filename=photo.jpg'
        return response

我的所有图像现在都带有水印。但问题是，作为用户，如果我下载这些图像，我发现下载的图像也带有水印，但我想下载实际图像，而不是带水印的图像，我该怎么办解决这个问题？

Answer 1

您需要将带水印的图像存储到不同的文件中。首先，您需要创建另一个列来存储带水印的图像。

class Photo(models.Model):
    ...
    watermarked_photo = ImageField()

然后，当您将带水印的图像保存到该列中时。

from PIL import Image
def image_watermark(request,image_id):
    photo = Photo.objects.get(pk=image_id)

    # Only need to watermark when there's no watermark
    if not photo.watermarked_photo.name:
        photo.watermarked_photo.name = 'watermarked_' + photo.photo.name
        watermark = Image.open('{0}/{1}'.format(settings.MEDIA_ROOT,'wmark.png'))
        img = Image.open(photo.photo.file)
        img.paste(watermark,(img.size[0]-watermark.size[0],img.size[1]- watermark.size[1]),watermark)
        img.save('{0}/{1}'.format(settings.MEDIA_ROOT, photo.watermarked_photo.name), quality=80)
        photo.save()

    wrapper = FileWrapper(open(photo.watermarked_photo.url, 'rb'))
    response = StreamingHttpResponse(wrapper, 'image/jpeg')
    response['Content-Disposition'] = 'attachment; filename=photo.jpg'
    return response

我的 Django 技能有点生疏，所以如果不做一些修改，这段代码可能无法工作。但这个想法应该是扎实的。

如果您只想使用临时文件，请尝试此

from PIL import Image
import tempfile

def image_watermark(request,image_id):
    photo = Photo.objects.get(pk=image_id)
    watermark = Image.open('{0}/{1}'.format(settings.MEDIA_ROOT,'wmark.png'))
    img = Image.open(photo.photo.file)
    img.paste(watermark,(img.size[0]-watermark.size[0],img.size[1]- watermark.size[1]),watermark)

    tmpfile = tempfile.TemporaryFile()
    img.save(tmpfile, img.format, quality=80)

    tmpfile.seek(0)
    wrapper = FileWrapper(tmpfile)
    response = StreamingHttpResponse(wrapper, 'image/jpeg')
    response['Content-Disposition'] = 'attachment; filename=photo.jpg'
    return response