I'm currently using the below code to put an image on top of another image
Stream stream = client.OpenRead(some URL here);
Bitmap baseimg = (Bitmap)System.Drawing.Image.FromStream(stream);
Bitmap ovlimg = (Bitmap)System.Drawing.Image.FromFile("fanmade.png");
var finalImage = new Bitmap(baseimg.Width, baseimg.Height);
var graphics = Graphics.FromImage(finalImage);
graphics.CompositingMode = CompositingMode.SourceOver;
graphics.DrawImage(baseimg, 0, 0);
graphics.DrawImage(ovlimg, 0, 0);
finalImage.Save("1.png", System.Drawing.Imaging.ImageFormat.Png);
However, the file size turns out to be a lot bigger than expected from 6-9 Mb to 16Mb. So I'm trying to find a more efficient way that would make the file size smaller while still keeping the image quality
Here are both the images
The Base IMG (Changes based on the user input but here's an example): https://pasteboard.co/K6hCXng.png
The overlay IMG: https://pasteboard.co/K6hDvIc.png
Related
Yes yes... I've seen other posts related to this issue, and yes... I've googled about it.
But so far, I was not able to get to the result I need.
I'm loading a large image taken in 300 dpi, and I need to resize it.
I know... I know... dpi is relative and doesn't really matter... what matters are the dimensions in pixels:
DPI is essentially the number of pixels that correspond to an inch when the image is printed not when it is viewed on a screen. Therefore by increasing the DPI of the image, you do not increase the size of the image on the screen. You only increase the quality of print.
Even though the DPI information stored in the EXIF of an image is somewhat useless, it is causing me problems.
The image I'm resizing is losing the original exif information, including the horizontal and vertical resolution (dpi), and thus it is saving with a default of 96 dpi. Possible reason to this is that only JPEG and another format can hold metadata information.
The end image result is should look like this: 275x375 at 300dpi
Instead is looking like this: 275x375 at 96dpi
You can argue that they are they same, and I agree, but we have a corel draw script that used to load these images, and since this dpi information is different, it places it in different sizes on the document.
Here's what I'm using for resizing:
public System.Drawing.Bitmap ResizeImage(System.Drawing.Image image, int width, int height)
{
Bitmap result = new Bitmap(width, height);
// set the resolutions the same to avoid cropping due to resolution differences
result.SetResolution(image.HorizontalResolution, image.VerticalResolution);
//use a graphics object to draw the resized image into the bitmap
using (Graphics graphics = Graphics.FromImage(result))
{
//set the resize quality modes to high quality
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//draw the image into the target bitmap
graphics.DrawImage(image, 0, 0, result.Width, result.Height);
}
//return the resulting bitmap
return result;
}
That does the work very well, but loses the EXIF information.
Setting the SetResolution to SetResolution(300, 300) does not work!
I looked at reading and changing the EXIF information of an image, and I've tried:
public void setImageDpi(string Filename, string NewRes)
{
Image Pic;
PropertyItem[] PropertyItems;
byte[] bDescription = new Byte[NewRes.Length];
int i;
string FilenameTemp;
System.Drawing.Imaging.Encoder Enc = System.Drawing.Imaging.Encoder.Transformation;
EncoderParameters EncParms = new EncoderParameters(1);
EncoderParameter EncParm;
ImageCodecInfo CodecInfo = GetEncoderInfo("image/jpeg");
// copy description into byte array
for (i = 0; i < NewRes.Length; i++) bDescription[i] = (byte)NewRes[i];
// load the image to change
Pic = Image.FromFile(Filename);
foreach (PropertyItem item in Pic.PropertyItems)
{
if (item.Id == 282 || item.Id == 283)
{
PropertyItem myProperty = item;
myProperty.Value = bDescription;
myProperty.Type = 2;
myProperty.Len = NewRes.Length;
Pic.SetPropertyItem(item);
Console.WriteLine(item.Type);
}
}
// we cannot store in the same image, so use a temporary image instead
FilenameTemp = Filename + ".temp";
// for lossless rewriting must rotate the image by 90 degrees!
EncParm = new EncoderParameter(Enc, (long)EncoderValue.TransformRotate90);
EncParms.Param[0] = EncParm;
// now write the rotated image with new description
Pic.Save(FilenameTemp, CodecInfo, EncParms);
// for computers with low memory and large pictures: release memory now
Pic.Dispose();
Pic = null;
GC.Collect();
// delete the original file, will be replaced later
System.IO.File.Delete(Filename);
// now must rotate back the written picture
Pic = Image.FromFile(FilenameTemp);
EncParm = new EncoderParameter(Enc, (long)EncoderValue.TransformRotate270);
EncParms.Param[0] = EncParm;
Pic.Save(Filename, CodecInfo, EncParms);
// release memory now
Pic.Dispose();
Pic = null;
GC.Collect();
// delete the temporary picture
System.IO.File.Delete(FilenameTemp);
}
That didn't work either.
I tried looking and changing the EXIF information for DPI (282 and 283) later in the process as such:
Encoding _Encoding = Encoding.UTF8;
Image theImage = Image.FromFile("somepath");
PropertyItem propItem282 = theImage.GetPropertyItem(282);
propItem282.Value = _Encoding.GetBytes("300" + '\0');
theImage.SetPropertyItem(propItem282);
PropertyItem propItem283 = theImage.GetPropertyItem(283);
propItem283.Value = _Encoding.GetBytes("300" + '\0');
theImage.SetPropertyItem(propItem283);
theImage.Save("somepath");
But the program crashes saying that Property Cannot be Found.
If the property doesn't exist, apparently I can't add it:
A PropertyItem is not intended to be used as a stand-alone object. A PropertyItem object is intended to be used by classes that are derived from Image. A PropertyItem object is used to retrieve and to change the metadata of existing image files, not to create the metadata. Therefore, the PropertyItem class does not have a defined Public constructor, and you cannot create an instance of a PropertyItem object.
I'm stuck... all I need is a resized image with a dpi set to 300, it shouldn't be so hard.
Any help much appreciated. Thanks
The following code worked for me:
const string InputFileName = "test_input.jpg";
const string OutputFileName = "test_output.jpg";
var newSize = new Size(640, 480);
using (var bmpInput = Image.FromFile(InputFileName))
{
using (var bmpOutput = new Bitmap(bmpInput, newSize))
{
foreach (var id in bmpInput.PropertyIdList)
bmpOutput.SetPropertyItem(bmpInput.GetPropertyItem(id));
bmpOutput.SetResolution(300.0f, 300.0f);
bmpOutput.Save(OutputFileName, ImageFormat.Jpeg);
}
}
When I inspect the output file I can see EXIF data and the DPI has been changed to 300.
i have colde like this :
Bitmap bmp = new Bitmap(width, height);
I just take a capture of window. Now i want just resize this captured bitmap (bmp).
How can i cut my bmp for example
RECT rt = new RECT();
GetWindowRect(hwnd1, out rt);
Int32 width = rt.Right - rt.Left;
Int32 height = rt.Bottom - rt.Top;
int leftttt = rt.Left + (width - 202);
int width2 = rt.Right - leftttt;
// // I want cut like this :
//
// in x=lefttt y = rt.Top Size ( width2,height)
And later i can easy save file to check my results by: (but won't do that only for check)
bmp.Save(#"D:\test.jpg", ImageFormat.Jpeg);
EDIT: I Want just cut not resize .
When i do code :
var graph = Graphics.FromImage(scren_kurwa.Image);
graph.DrawImage(bmp.Image, 10, 10, 200, 200);
And i save it its just override my bmp screen and just take a capture just in smaller version.
I just want to cut for examaple i want show only 1/4 of width this screen and save it to file. ( just save 1/4 width not more).
EDIT 2 :
graph.CopyFromScreen(leftttt, rt.Top, 0, 0, new Size(width2, height), CopyPixelOperation.SourceCopy);
This code above just doing what i want but i don't want again copy from screen i want copy this from bmp captured before.
Please be patient for newbies . I searched forums and just can't find solution.
Thank you.
EDIT 3
I just did how you wrote :
Rectangle cropRect = new Rectangle(100,100,100,100);
Bitmap bmp1 = new Bitmap(bmp1.Image);
bmp1.Clone(cropRect, bmp.PixelFormat);
bmp1.Save(#"D:\xdddde.jpg", ImageFormat.Jpeg);
But it don't cut an image just display the same as i had bmp.
This should work for you:
Bitmap cuttedImage;
using(Bitmap originalImage = new Bitmap("filePathName"))
{
Rectangle cropRect = new Rectangle(...);
cuttedImage = originalImage .Clone(cropRect, originalBmp.PixelFormat);
}
cuttedImage.Save("filePathName", ImageFormat.Jpeg);
cuttedImage.Dispose();
Note that this will create a shallow copy of your Bitmap. In your case that does not seem to be a problem, but keep that in mind.
Also make sure to check the MSDN documentation for exception handling. Either check that the rectangle is bigger than 0 and not bigger than the original image beforehand or catch the exceptions.
Yes yes... I've seen other posts related to this issue, and yes... I've googled about it.
But so far, I was not able to get to the result I need.
I'm loading a large image taken in 300 dpi, and I need to resize it.
I know... I know... dpi is relative and doesn't really matter... what matters are the dimensions in pixels:
DPI is essentially the number of pixels that correspond to an inch when the image is printed not when it is viewed on a screen. Therefore by increasing the DPI of the image, you do not increase the size of the image on the screen. You only increase the quality of print.
Even though the DPI information stored in the EXIF of an image is somewhat useless, it is causing me problems.
The image I'm resizing is losing the original exif information, including the horizontal and vertical resolution (dpi), and thus it is saving with a default of 96 dpi. Possible reason to this is that only JPEG and another format can hold metadata information.
The end image result is should look like this: 275x375 at 300dpi
Instead is looking like this: 275x375 at 96dpi
You can argue that they are they same, and I agree, but we have a corel draw script that used to load these images, and since this dpi information is different, it places it in different sizes on the document.
Here's what I'm using for resizing:
public System.Drawing.Bitmap ResizeImage(System.Drawing.Image image, int width, int height)
{
Bitmap result = new Bitmap(width, height);
// set the resolutions the same to avoid cropping due to resolution differences
result.SetResolution(image.HorizontalResolution, image.VerticalResolution);
//use a graphics object to draw the resized image into the bitmap
using (Graphics graphics = Graphics.FromImage(result))
{
//set the resize quality modes to high quality
graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;
graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//draw the image into the target bitmap
graphics.DrawImage(image, 0, 0, result.Width, result.Height);
}
//return the resulting bitmap
return result;
}
That does the work very well, but loses the EXIF information.
Setting the SetResolution to SetResolution(300, 300) does not work!
I looked at reading and changing the EXIF information of an image, and I've tried:
public void setImageDpi(string Filename, string NewRes)
{
Image Pic;
PropertyItem[] PropertyItems;
byte[] bDescription = new Byte[NewRes.Length];
int i;
string FilenameTemp;
System.Drawing.Imaging.Encoder Enc = System.Drawing.Imaging.Encoder.Transformation;
EncoderParameters EncParms = new EncoderParameters(1);
EncoderParameter EncParm;
ImageCodecInfo CodecInfo = GetEncoderInfo("image/jpeg");
// copy description into byte array
for (i = 0; i < NewRes.Length; i++) bDescription[i] = (byte)NewRes[i];
// load the image to change
Pic = Image.FromFile(Filename);
foreach (PropertyItem item in Pic.PropertyItems)
{
if (item.Id == 282 || item.Id == 283)
{
PropertyItem myProperty = item;
myProperty.Value = bDescription;
myProperty.Type = 2;
myProperty.Len = NewRes.Length;
Pic.SetPropertyItem(item);
Console.WriteLine(item.Type);
}
}
// we cannot store in the same image, so use a temporary image instead
FilenameTemp = Filename + ".temp";
// for lossless rewriting must rotate the image by 90 degrees!
EncParm = new EncoderParameter(Enc, (long)EncoderValue.TransformRotate90);
EncParms.Param[0] = EncParm;
// now write the rotated image with new description
Pic.Save(FilenameTemp, CodecInfo, EncParms);
// for computers with low memory and large pictures: release memory now
Pic.Dispose();
Pic = null;
GC.Collect();
// delete the original file, will be replaced later
System.IO.File.Delete(Filename);
// now must rotate back the written picture
Pic = Image.FromFile(FilenameTemp);
EncParm = new EncoderParameter(Enc, (long)EncoderValue.TransformRotate270);
EncParms.Param[0] = EncParm;
Pic.Save(Filename, CodecInfo, EncParms);
// release memory now
Pic.Dispose();
Pic = null;
GC.Collect();
// delete the temporary picture
System.IO.File.Delete(FilenameTemp);
}
That didn't work either.
I tried looking and changing the EXIF information for DPI (282 and 283) later in the process as such:
Encoding _Encoding = Encoding.UTF8;
Image theImage = Image.FromFile("somepath");
PropertyItem propItem282 = theImage.GetPropertyItem(282);
propItem282.Value = _Encoding.GetBytes("300" + '\0');
theImage.SetPropertyItem(propItem282);
PropertyItem propItem283 = theImage.GetPropertyItem(283);
propItem283.Value = _Encoding.GetBytes("300" + '\0');
theImage.SetPropertyItem(propItem283);
theImage.Save("somepath");
But the program crashes saying that Property Cannot be Found.
If the property doesn't exist, apparently I can't add it:
A PropertyItem is not intended to be used as a stand-alone object. A PropertyItem object is intended to be used by classes that are derived from Image. A PropertyItem object is used to retrieve and to change the metadata of existing image files, not to create the metadata. Therefore, the PropertyItem class does not have a defined Public constructor, and you cannot create an instance of a PropertyItem object.
I'm stuck... all I need is a resized image with a dpi set to 300, it shouldn't be so hard.
Any help much appreciated. Thanks
The following code worked for me:
const string InputFileName = "test_input.jpg";
const string OutputFileName = "test_output.jpg";
var newSize = new Size(640, 480);
using (var bmpInput = Image.FromFile(InputFileName))
{
using (var bmpOutput = new Bitmap(bmpInput, newSize))
{
foreach (var id in bmpInput.PropertyIdList)
bmpOutput.SetPropertyItem(bmpInput.GetPropertyItem(id));
bmpOutput.SetResolution(300.0f, 300.0f);
bmpOutput.Save(OutputFileName, ImageFormat.Jpeg);
}
}
When I inspect the output file I can see EXIF data and the DPI has been changed to 300.
I want to draw an image by reading it
from file sytem image file, and render
it on a document, below:
if (File.Exists(imageFilePath)) //all image file are 16*16 in pixel
{
Bitmap bitmap = new Bitmap(18, 18);
Graphics graphics = Graphics.FromImage(bitmap);
Image image = Image.FromFile(imageFilePath);
graphics.DrawImage(image, 1, 1); //1 pixel space in between
}
However, gray images renders the
correct size (18*18 in pixel),
whereas, colour images are cut off, or
have to increase the BitMap size (e.g.
Bitmap(23, 23). I want to all images
have the same size! The image sizes
are all the same on the file system.
It is a bit of urgency. Any idea would
be very much appreicated!
Solution below:
if (File.Exists(imageFilePath))
{
Bitmap bitmap = new Bitmap(18, 18);
Graphics graphics = Graphics.FromImage(bitmap);
Image image = Image.FromFile(imageFilePath);
graphics.DrawImage(image, 1, 1, **18, 18**);
}
Alright, I have an image coming through from an external application in an 8-bit indexed format. I need this image converted to a 24-bit format of the exact same size.
I've tried creating a new Bitmap of the same size and of type Format24bppRgb and then using a Graphics object to draw the 8-bit image over it before saving it as a Bmp. This approach doesn't error out but when I open the resulting image the BMP header has all kinds of funky values. The height and width are HUGE and, in addition, there are funny (and large) values for the compression flags and a few others. Unfortunately my particular requirements are to pass this file off to a specific printer driver that demands a 24-bit image with specific header values (which I'm trying to achieve through GDI+)
Anyone know of an example on "up-converting" an indexed file to a not-indexed 24-bit file? If not an example, which path should I start down to write my own?
-Kevin Grossnicklaus
kvgros#sseinc.com
I used the code below to "up-convert" an image from 8bpp to 24bpp. Inspecting the generated 24bpp file with a hex editor and comparing against the 8bpp file shows no difference in height and width in the two files. That is, the 8bpp image was 1600x1200, and the 24bpp image has the same values.
private static void ConvertTo24(string inputFileName, string outputFileName)
{
Bitmap bmpIn = (Bitmap)Bitmap.FromFile(inputFileName);
Bitmap converted = new Bitmap(bmpIn.Width, bmpIn.Height, PixelFormat.Format24bppRgb);
using (Graphics g = Graphics.FromImage(converted))
{
// Prevent DPI conversion
g.PageUnit = GraphicsUnit.Pixel
// Draw the image
g.DrawImageUnscaled(bmpIn, 0, 0);
}
converted.Save(outputFileName, ImageFormat.Bmp);
}
Everything else in the headers looks reasonable, and the images display identical on my system. What "funky values" are you seeing?
This is my conversion code. Notice the matching of resolution between source image and resulting image.
private void ConvertTo24bppPNG(Stream imageDataAsStream, out byte[] data)
{
using ( Image img = Image.FromStream(imageDataAsStream) )
{
using ( Bitmap bmp = new Bitmap(img.Width, img.Height, PixelFormat.Format24bppRgb) )
{
// ensure resulting image has same resolution as source image
// otherwise resulting image will appear scaled
bmp.SetResolution(img.HorizontalResolution, img.VerticalResolution);
using ( Graphics gfx = Graphics.FromImage(bmp) )
{
gfx.DrawImage(img, 0, 0);
}
using ( MemoryStream ms = new MemoryStream() )
{
bmp.Save(ms, ImageFormat.Png);
data = new byte[ms.Length];
ms.Position = 0;
ms.Read(data, 0, (int) ms.Length);
}
}
}
}
It seems odd that you're creating a Bitmap of the same width and height as your input, yet the generated BMP is much larger. Can you post some code?
The problem is probably the difference between the Vertical- and HorizontalResolution of your source image and your output image. If you load a 8bpp indexed bitmap with a resolution of 72 DPI, and then create a new 24bpp bitmap (default resolution will be 96 DPI... at least it is on my system) and then use Graphics.DrawImage to blit to the new bitmap, your image will appear slightly zoomed in and cropped.
Having said that, I don't know off the top of my head how to properly create the output Bitmap and/or Graphics object to scale properly when saved. I suspect it will have something to do with creating the images using a common scale like inches instead of pixels.