Does anybody know how to properly identify CMYK images in ASP.NET using C#? When I check the Flags attribute of a Bitmap instance, I get incorrect results.
I have created three images to test this: cmyk.jpg, rgb.jpg and gray.jpg. These are respectively CMYK, RGB and Grayscale images.
This is my test code:
static void Main(string[] args)
{
Bitmap bmpCMYK = new Bitmap("cmyk.jpg");
Bitmap bmpRGB = new Bitmap("rgb.jpg");
Bitmap bmpGray = new Bitmap("gray.jpg");
Console.WriteLine("\t\tRgb\tCmyk\tGray\tYcbcr\tYcck\tPixelFormat");
Console.WriteLine("cmyk.jpg\t{0}\t{1}\t{2}\t{3}\t{4}\t{5}",
IsSet(bmpCMYK, System.Drawing.Imaging.ImageFlags.ColorSpaceRgb),
IsSet(bmpCMYK, System.Drawing.Imaging.ImageFlags.ColorSpaceCmyk),
IsSet(bmpCMYK, System.Drawing.Imaging.ImageFlags.ColorSpaceGray),
IsSet(bmpCMYK, System.Drawing.Imaging.ImageFlags.ColorSpaceYcbcr),
IsSet(bmpCMYK, System.Drawing.Imaging.ImageFlags.ColorSpaceYcck),
bmpCMYK.PixelFormat);
Console.WriteLine("rgb.jpg\t\t{0}\t{1}\t{2}\t{3}\t{4}\t{5}",
IsSet(bmpRGB, System.Drawing.Imaging.ImageFlags.ColorSpaceRgb),
IsSet(bmpRGB, System.Drawing.Imaging.ImageFlags.ColorSpaceCmyk),
IsSet(bmpRGB, System.Drawing.Imaging.ImageFlags.ColorSpaceGray),
IsSet(bmpRGB, System.Drawing.Imaging.ImageFlags.ColorSpaceYcbcr),
IsSet(bmpRGB, System.Drawing.Imaging.ImageFlags.ColorSpaceYcck),
bmpRGB.PixelFormat);
Console.WriteLine("gray.jpg\t{0}\t{1}\t{2}\t{3}\t{4}\t{5}",
IsSet(bmpGray, System.Drawing.Imaging.ImageFlags.ColorSpaceRgb),
IsSet(bmpGray, System.Drawing.Imaging.ImageFlags.ColorSpaceCmyk),
IsSet(bmpGray, System.Drawing.Imaging.ImageFlags.ColorSpaceGray),
IsSet(bmpGray, System.Drawing.Imaging.ImageFlags.ColorSpaceYcbcr),
IsSet(bmpGray, System.Drawing.Imaging.ImageFlags.ColorSpaceYcck),
bmpGray.PixelFormat);
bmpCMYK.Dispose();
bmpRGB.Dispose();
bmpGray.Dispose();
Console.ReadLine();
}
private static bool IsSet(Bitmap bitmap, System.Drawing.Imaging.ImageFlags flag)
{
return (bitmap.Flags & (int)flag) == (int)flag;
}
This produces the following output:
I have checked the actual images and cmyk.jpg really is a CMYK image.
Apparently, this is a "known issue". Alex Gil had the same problem in WPF (see this question: How to identify CMYK images using C#) and he managed to solve it by using a BitmapDecoder class to load the images. I'm a bit uncomfortable using that solution in ASP.NET because it requires me to add references to WindowsBase.dll and PresentationCore.dll and I'm not sure I want those in a web project.
Does anyone know of any other pure .NET solutions to check if an image is in the CMYK format that I can safely use in ASP.NET?
I use a combination of the ImageFlags and PixelFormat values. Note that PixelFormat.Forma32bppCMYK is missing from .NET - I grabbed it out of GdiPlusPixelFormats.h in the Windows SDK.
The trick is that Windows 7 and Server 2008 R2 returns the correct pixel format but is missing the image flags. Vista and Server 2008 return an invalid pixel format but the correct image flags. Insanity.
public ImageColorFormat GetColorFormat(this Bitmap bitmap)
{
const int pixelFormatIndexed = 0x00010000;
const int pixelFormat32bppCMYK = 0x200F;
const int pixelFormat16bppGrayScale = (4 | (16 << 8);
// Check image flags
var flags = (ImageFlags)bitmap.Flags;
if (flags.HasFlag(ImageFlags.ColorSpaceCmyk) || flags.HasFlag(ImageFlags.ColorSpaceYcck))
{
return ImageColorFormat.Cmyk;
}
else if (flags.HasFlag(ImageFlags.ColorSpaceGray))
{
return ImageColorFormat.Grayscale;
}
// Check pixel format
var pixelFormat = (int)bitmap.PixelFormat;
if (pixelFormat == pixelFormat32bppCMYK)
{
return ImageColorFormat.Cmyk;
}
else if ((pixelFormat & pixelFormatIndexed) != 0)
{
return ImageColorFormat.Indexed;
}
else if (pixelFormat == pixelFormat16bppGrayScale)
{
return ImageColorFormat.Grayscale;
}
// Default to RGB
return ImageColorFormat.Rgb;
}
public enum ImageColorFormat
{
Rgb,
Cmyk,
Indexed,
Grayscale
}
An idea: If you dont want to reference those dll's in your web project, you could do the processing outside the web project, in a service, which may be better anyway?
You might check out FreeImage which is a win32 DLL but has a .NET wrapper, I am using it in a production enviroment and it's great.
I would be surprised if it couldn't provide this information.
(edit) I didn't notice before you asked for pure .NET solutions - so maybe this won't work - but I have found it a useful supplement to the limitations of the .NET framework for image manipulation.
Another idea, if you only need to identify the format, is to extract that directly from the file. I have no idea how complex the specification for the JPEG format might be, but hey, it's only 29 pages!
As previously answered, the most reliable way will be to parse the file's header to retrieve this data.
So here is how I solved the issue you were having which was the same as what I was having. Everything in csharp looks to return rgb info when you know it's a 100% a cymk image. So what to do, well go to the root and read the file. Here is what I had done and tested to work well and should cover all OS's, and 50 for 50 imgs tested right. This is 2.0 too just in case.
public bool isByteACMYK(Stream image)
{
using (StreamReader sr = new StreamReader(image))
{
string contents = sr.ReadToEnd();
if (contents.ToLower().Contains("cmyk"))
{
return true;
}
}
return false;
}
public bool isFileACMYKJpeg(System.Drawing.Image image)
{
System.Drawing.Imaging.ImageFlags flagValues = (System.Drawing.Imaging.ImageFlags)Enum.Parse(typeof(System.Drawing.Imaging.ImageFlags), image.Flags.ToString());
if (flagValues.ToString().ToLower().IndexOf("ycck") == -1)
{
// based on http://www.maxostudio.com/Tut_CS_CMYK.cfm
bool ret = false;
try{
int cmyk = (image.Flags & (int)ImageFlags.ColorSpaceCmyk);
int ycck = (image.Flags & (int)ImageFlags.ColorSpaceYcck);
ret = ((cmyk > 0) || (ycck > 0));
} catch (Exception ex){
}
return ret;
}
return true;
}
// my upload test .. but you could turn a file to stream and do the same
public void UpdatePool(HttpPostedFile newimage)
{
if (newimage.ContentLength != 0)
{
Stream stream = newimage.InputStream;
MemoryStream memoryStream = new MemoryStream();
CopyStream(stream,memoryStream);
memoryStream.Position = 0;
stream = memoryStream;
System.Drawing.Image processed_image = null;
processed_image = System.Drawing.Image.FromStream(newimage.InputStream);
if (imageService.isFileACMYKJpeg(processed_image) || imageService.isByteACMYK(stream))
{
Flash["error"] = "You have uploaded a CMYK image. Please conver to RGB first.";
RedirectToReferrer();
return;
}
}
}
cheers - Jeremy
I was under the assumption that everything in .NET was based on RGB, aRGB and grayscale (as grayscale is RGB(128, 128, 128)).
If my assumption is correct then you will have to go the third party route.
Related
So for some project i'm working with Xamarin.Forms.
Since one area is just unbearably slow with Xamarin.Forms i've used a CustomRenderer to solve one particular area where a list is involved.
After getting back to the project and upgrading packages, i've suddenly got the weirdest bug.
I am setting "1234" to an EditText, and the EditText.Text Property is suddenly "49505152" - the string is converted to its ascii equivalent.
Is this a known issue? Does anyone know how to fix it?
The cause of the issue was that my EditText had an InputFilter applied and that after updating a package suddenly another code path of FilterFormatted was executed.
public ICharSequence FilterFormatted(ICharSequence source, int start, int end, ISpanned dest, int dstart, int dend)
{
var startSection = dest.SubSequenceFormatted(0, dstart);
var insert = source.SubSequenceFormatted(start, end);
var endSection = dest.SubSequenceFormatted(dstart, dest.Length());
var merged = $"{startSection}{insert}{endSection}";
if (ValidationRegex.IsMatch(merged) && InputRangeCheck(merged, CultureInfo.InvariantCulture))
{
StringBuilder sb = new StringBuilder(end - start);
for (int i = start; i < end; i++)
{
char c = source.CharAt(i);
sb.Append(c);
}
if (source is ISpanned) {
SpannableString sp = new SpannableString(sb);
TextUtils.CopySpansFrom((ISpanned)source, start, sb.Length(), null, sp, 0);
return sp;
} else {
// AFTER UPDATE THIS PATH WAS ENTERED UNLIKE BEFORE
return sb;
}
}
else
{
return new SpannableString(string.Empty);
}
}
I am writing an app on top media foundation under win 7, I use IMFMediaSource to query the cameras interfaces to get frames and other properties. its weird but I cant find a way to change resolution. it seems that if I used IMFCaptureSource i could use SetCurrentDeviceMediaType to change resolution but its only supported in Windows 8. so we cant change resolution under win 7 using media foundation?? is there a way to use direct show with IMFMediaSource to change resolution??
if so, can anyone help with some code sample?
thanks!
ok, so I found out eventually. Iam using IMFSourceReader to get samples from the MFMediaSource, so after configurating the SourceReader you can iterate the native media types that the camera supports like this :
HRESULT nativeTypeErrorCode = S_OK;
DWORD count = 0;
UINT32 streamIndex = 0;
UINT32 requiredWidth = 1600;
UINT32 requiredheight = 900;
while (nativeTypeErrorCode == S_OK)
{
IMFMediaType * nativeType = NULL;
nativeTypeErrorCode = m_pReader->GetNativeMediaType(streamIndex, count, &nativeType);
if(nativeTypeErrorCode != S_OK) continue;
// get the media type
GUID nativeGuid = {0};
hr = nativeType->GetGUID(MF_MT_SUBTYPE, &nativeGuid);
if (FAILED(hr)) return hr;
UINT32 width, height;
hr = ::MFGetAttributeSize(nativeType, MF_MT_FRAME_SIZE, &width, &height);
if (FAILED(hr)) return hr;
if(nativeGuid == <my type guid> && width == requiredWidth && height == requiredheight)
{
// found native config, set it
hr = m_pReader->SetCurrentMediaType(streamIndex, NULL, nativeType);
if (FAILED(hr)) return hr;
break;
}
SafeRelease(&nativeType);
count++;
}
this means that Iam not creating a new media type with the resolution I require, I get the native media type with the configuration I need, and I set it on the SourceReader.
hope it will help the future media foundation traveler... :)
You can query directshow interface from IMediaSource which can change resolution.
for ex:for Camera control properties I do like this.
IAMCameraControl* m_pCameraControl = NULL;
HRESULT hr = S_OK;
hr = pMediaSource->QueryInterface(IID_PPV_ARGS(&m_pCameraControl));
if (m_pCameraControl == NULL)
{
return E_FAIL;
}
In the same way in your case I am not sure about the interface but I guess it will be in following way.
IAMStreamConfig * m_pStreamConfig = NULL;
HRESULT hr = S_OK;
hr = pMediaSource->QueryInterface(IID_PPV_ARGS(&m_pStreamConfig ));
if (m_pCameraControl == NULL)
{
return E_FAIL;
}
My scenario is this:
I create o custom report based on a stored procedure that returns three columns (person_id[long], name[varchar(100)], age[int], photo[image]). Those are the columns and types in my database table.
Right now i'm using something like this for each image of the report.
<img src="<%= Url.Action("ShowImage", "Reports", new {personId = result["PERSON_ID"]}) %>" />
with ShowImage being
public virtual ActionResult ShowImage(long? personId)
{
try
{
if (personId.HasValue)
{
byte[] imageArray = StudentClient.GetPersonPhotoById(personId.Value);
if (imageArray == null)
return File(noPhotoArray, "image/jpg");
#region Validate that the uploaded picture is an image - temporary code
// Get Mime Type
byte[] buffer = new byte[256];
buffer = imageArray.Take(imageArray.Length >= 256 ? 256 : imageArray.Length).ToArray();
var mimeType = UrlmonMimeType.GetMimeType(buffer);
if (String.IsNullOrEmpty(mimeType) || mimeType.IndexOf("image") == -1)
return File(noPhotoArray, "image/jpg");
#endregion
return File(imageArray, "image/jpg");
}
}
catch
{
return File(noPhotoArray, "image/jpg");
}
}
I would like to use some sort of alternative because this is very stresful due to the fact the ShowImage() calls a service method StudentClient.GetPersonPhotoById(personId.Value); for every single picture, meaning allot of calls to the service and the DB also.
I would like to actually use that photo column that returns a byte array instead of using the Person_id column through the ShowImage controller method.
That would practicaly reduce the number of calls to the service to 0 and use the actual data from the image column. This seems pretty straight forward but I struggle to find a solution.
Thank you!
Simplest solution - use OutputCache. Moreover, you can set cache location to client, and the browser will cache the images once they're downloaded. VaryByParam will give you the ability to cache images depending on personId.
There's quite a neat technique where you can stream the binary data directly from the SQL Server to the client, via the webserver.
This is my code for doing it:
public void StreamFile(Stream stream)
{
DbDataReader dr = LoadDbStream();
if (!dr.Read())
return;
const int BUFFERSIZE = 512;
byte[] Buffer = new byte[BUFFERSIZE];
long StartIndex = 0;
long Read = dr.GetBytes(0, StartIndex, Buffer, 0, BUFFERSIZE);
while (Read == BUFFERSIZE)
{
stream.Write(Buffer, 0, BUFFERSIZE);
StartIndex += BUFFERSIZE;
Read = dr.GetBytes(0, StartIndex, Buffer, 0, BUFFERSIZE);
}
stream.Write(Buffer, 0, (int)Read);
}
private DbDataReader LoadDbStream()
{
DbCommand cmd = Cms.Data.GetCommand("SELECT Data FROM CMS_Files WHERE FileId = #FileId", "#FileId", Id.ToString());
cmd.CommandType = System.Data.CommandType.Text;
cmd.Connection.Open();
return cmd.ExecuteReader(CommandBehavior.SequentialAccess | CommandBehavior.CloseConnection);
}
The command object is an ordinary command object. The key part is the CommandBehavior.SequentialAccess flag as this makes sql server only send data when you ask for. You therefore can only read the columns in the order they are specified in the query. the other point to make is stream should be the outputstream from the request & switch output buffering off.
Couple this with outputcaching and you reduce the memory load on the server.
Simon
You can use this as source form the image.
src="data:image/jpg;base64,<%= System.Convert.ToBase64String(result["PHOTO"] as byte[]) %>"
i use this code to create thumbnails
System.Drawing.Image.GetThumbnailImageAbort abort = new System.Drawing.Image.GetThumbnailImageAbort(this.ThumbnailCallback);
System.Drawing.Image image2 = image.GetThumbnailImage((int)Math.Round((double)wid / difference), (int)Math.Round((double)hei / difference), abort, IntPtr.Zero);
image2.Save(str2, System.Drawing.Imaging.ImageFormat.Jpeg);
image2.Dispose();
but i get this very low quality image
but it is suposed to be like this one
what i am making wrong
or how can achieve this
Your problem is not really with the GetThumbnailImage() method, but instead in how you are saving the file. You need to specify the quality level of the JPEG you are saving, or it seems it always defaults to a very low value.
Consider this code as a guide (it's from an old .NET 2.0 project; the code still works fine compiled against 4.0, but there may be a more direct method in 4.0; I've never had reason to check)
ImageCodecInfo[] encoders = ImageCodecInfo.GetImageEncoders();
ImageCodecInfo jpegEncoder = null;
for (int x = 0; x < encoders.Length; x++) {
if (string.Compare(encoders[x].MimeType, "image/jpeg", true) == 0) {
jpegEncoder = encoders[x];
break;
}
}
if (jpegEncoder == null) throw new ApplicationException("Could not find JPEG encoder!");
EncoderParameters prms = new EncoderParameters(1);
prms.Param[0] = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 80L);
bitmap.Save(fileName, jpegEncoder, prms);
Here is another solution that should always work without fetching out the encoder. It resizes keeping relation between width & heigh ... modify for your needs.
/// <summary>
/// Resize an image with high quality
/// </summary>
public static Image ResizeImage(Image srcImage, int width)
{
var b = new Bitmap(width, srcImage.Height * width / srcImage.Width);
using (var g = Graphics.FromImage((Image)b))
{
g.InterpolationMode = InterpolationMode.HighQualityBicubic;
g.DrawImage(srcImage, 0, 0, b.Width, b.Height);
}
return b;
}
How to get folder size in Adobe Air?
Should be fairly simple using File.size. Just in case is confusing, folders in AIR are represented using the File class, which extends FileReference, thus the link to the FileReference documentation.
Recursive folder listings and contents processing
http://cookbooks.adobe.com/post_Recursive_folder_listings_and_contents_processing-9410.html
...has sufficient sample code in it to get you started.
my implementation is:
public static function getFileSize(file:File):Number{
var result:Number = 0;
if(file == null || file.exists == false) {
return 0;
}
if(file.isDirectory){
var files:Array = file.getDirectoryListing();
for each (var f:File in files) {
if(f.isDirectory){
result += getFileSize(f);
}else{
result += f.size;
}
}
}else{
return file.size;
}
return result;
}