image processing - Rotating JPEGs in .NET with minimal loss of quality -

-

I am trying to rotate JPEG images from ASP.NET MVC (in increments of 90 degree increments). I'm trying to use the System.Drawing (GDI +), though I'm running into issues.

I tried to use that which is capable of rotating the image but causes the loss of quality. Even with the 100 encoder quality, there are still things that are visible on the rotated image which were not on the original image, nor when I used it to rotate it using other programs (gimp, etc.) I show. 

 Using  (image image = image.framefile ("C: \\ source.jpg")) {ImageFormat sourceFormat = image.RawFormat; Image.RotateFlip (RotateFlipType.Rotate90FlipNone); Encoder parameter encoder = null; Try (if (sourceFormat == ImageFormat.Jpeg) {encoder perm = new encoder parameter (1); Ankoderprmkpam [0] = new Ankoderpramitr (encoder. Quality, 100 L);} Image.Save ( "C: \ \ target.jpg ", GetEncoder (Srotformet), Ankoderprms);} finally {if (encoder perm! = null) encoder Params. Dispojh ();}}

I found an article Looks for the encoder.configuration from NOAT - although I can rotate it from any of my JPEG exams. Whether it is a value of dimension 16 or not. 

 using  (image image = image.framefile ("C: \\ source.jpg")) { ImageFormat sourceFormat = image.RawFormat; encoder parameters Ankoderprm = null; try (if (sourceFormat == ImageFormat.Jpeg) {encoder perm = new encoder parameter (1); encoder Paramskpam [0] = new Ankoderpramitr (encoder Ksnrcna , (Long) encoder value. Transformatate 90);} Image.Save ("C: \\ target.jpg", GetEncoder (source format), encoderprom);} end In {if (encoder perm! = Null) Encoder Params Dispos (); Does anyone know that in a way that jpeg successfully rotates in .net at 90 degree intervals, at least or without any loss, methods or any other method. Should use? Thank you.  
 Also, here is my  GetEncoder : 
 
  Private Image Kodekinfo GetEncoder (ImageFormat format) {foreach (varC ()) if (info. FormatID == format.Guid) Return information; Return tap; }  
 
 Edit: 
 
 I updated the above code to better match my actual code. The bug was in the following line: 
 
  if (sourceFormat == ImageFormat.Jpeg) { 
 
 it should have been: 
 
 < Code> if (sourceFormat.Guid == ImageFormat.Jpeg.Guid) {

any With the disintegration of the image by the method, it rotates and compresses it, you have a loss of quality.

JPEG format all the four compressed color information of the sections of 2x2 pixels obtained by color to represent pixels, so if your image width and height are divisible by two, so you less The quality will be lost because most of the information collected in the compression is the information that was launched in the decompression.

Similarly the brightness information is compressed to a square of 8x8 pixels, so if your width and height is divisible by eight, then the grid will align the image after rotating and you will lose less actual information .

The study, you must use fully diff first method, JPEG files to lossless rotation and change again each class of information and rotating to so that pressure without the rotated image and reprocess Makes it without


Comments

Post a Comment

Popular posts from this blog

c# - ListView onScroll event -

-
I am programming a simple C # application, and I need a Scallow event on the list view. So I inherited the original ListView class created in ListviewEx witch. I found out how to locate the scroll message from WinAPI and I modified the WndProc method. Now I have this WndProc: protected override zero WndProc (Ref message message) {base.WndProc (Ref I); If (m.msg == WM_VSCROLL) {onScroll (This, New EventArgs ()); }} But the problem is, I do not know how to know about scrolling information. This data should be in wParam, but there is a LOWORD macro ++ like in C in C # and I switch to find the criteria like SB_ below, SB_ENDSCROLL, SB_PAGEUP etc. there any way Need to change the LOWORD macro from C #? Or any other way to find the necessary parameters about scrolling? You can define the WParam constants as the following: Private const int WM_HSCROLL = 0x114; Private Constant WM_VSCROLL = 0x115; Private contact int SBHOZZ = 0; Private Consultant SB_VERT = 1; Private Con...
Read more

PHP - get image from byte array -

-
I am trying to create a back-end for my mobile application. I am sending the content of an image in the body of the HTTP request (output stream) as a byte array, I want to read this stream of bytes in PHP scripts and take back an image. Can anyone tell me how can I do this? Thank you. You can obtain the request body $ body = Reading from file_get_contents ('php: // input'); What you do with that data Depending on you, you can write the data in a file as you mentioned that this is image data, you can drop the data into the object can do. Another option is to use and load the image.
Read more

Linux Terminal Problem with Non-Canonical Terminal I/O app -

-
I have a small app written in C to run on Linux. Part of the app accepts user-input from keyboard , And it uses non-canonical terminal mode so that it can respond to each keystroke. The section of the code that accepts input is a simple task that is called repeatedly in the loop: char get_input () {char C = 0; Int res = reading (input_tamille, & amp; c, 1); If (RSS == 0) 0 returns; If (res == -1) {/ * snip error handling * /} return c; } It reads a letter from the terminal if there is no input within a given time limit, (c_cc [VTIME] value in the vocabulary structure), read () 0 And get_input () is called again It all works very well, I have recently discovered that if you run this app in a terminal window, and then the app Close the terminal window without ending, the app will not exit Received, but CPU intensive launches into an infinite loop, where the read () returns 0 without waiting continued. So how can I get out of the apple if it runs from the terminal win...
Read more