I have some background images stored as binary data. I need to draw something on it based on data and then show it as a single image in the browser. The issue is that some of the images are getting zoomed in and some get zoomed out when I try to do this with the following code. Can anyone please tell where I am going wrong?
int imageWidth = 0, imageHeight=0;
Image bmpImg;
if (datatable.Rows.Count > 0)
{
bmpImg = Bitmap.FromStream(new MemoryStream((byte[])datatable.Rows[0]["data"]));
imageWidth = bmpImg.Width;
imageHeight= bmpImg.Height;
}
else{
bmpImg = null;
}
bitmap = new Bitmap(imageWidth, imageHeight);
//bitmap = new Bitmap(1000, 800);
renderer = SvgRenderer.FromImage(bitmap);
graphics = Graphics.FromImage(bitmap);
if(bmpImg != null)
{
graphics.DrawImage(bmpImg, 0, 0);
}
//perform other drawings using graphics
MemoryStream ms = new MemoryStream();
bitmap.Save(ms, ImageFormat.Png);
bitmap.Dispose();
renderer.Dispose();
After some searching, I got the answer from another question : Graphics.DrawImage unexpectedly resizing image
Basically you have to change this:
graphics.DrawImage(bmpImg, 0, 0);
to
graphics.DrawImage(bmpImg,new Rectangle(0,0,imageWidth,imageHeight));
Related
As we have upgraded to net core 6 we are rewriting some of our code base. We have a tag helper in AspNet Core which generates a barcode. This currently uses System.Drawing and ZXing.
TagHelper Old version using System.Drawing - working (top barcode)
public override void Process(TagHelperContext context, TagHelperOutput output)
{
var margin = 0;
var qrCodeWriter = new ZXing.BarcodeWriterPixelData
{
Format = ZXing.BarcodeFormat.PDF_417,
Options = new ZXing.Common.EncodingOptions
{
Height = this.Height > 80 ? this.Height : 80,
Width = this.Width > 400 ? this.Width : 400,
Margin = margin
}
};
var pixelData = qrCodeWriter.Write(QRCodeContent);
// creating a bitmap from the raw pixel data; if only black and white colors are used it makes no difference
// that the pixel data ist BGRA oriented and the bitmap is initialized with RGB
using (var bitmap = new Bitmap(pixelData.Width, pixelData.Height, System.Drawing.Imaging.PixelFormat.Format32bppRgb))
using (var ms = new MemoryStream())
{
var bitmapData = bitmap.LockBits(new Rectangle(0, 0, pixelData.Width, pixelData.Height),
System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb);
try
{
// we assume that the row stride of the bitmap is aligned to 4 byte multiplied by the width of the image
System.Runtime.InteropServices.Marshal.Copy(pixelData.Pixels, 0, bitmapData.Scan0,
pixelData.Pixels.Length);
}
finally
{
bitmap.UnlockBits(bitmapData);
}
// save to stream as PNG
bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
output.TagName = "img";
output.Attributes.Clear();
output.Attributes.Add("width", Width);
output.Attributes.Add("height", Height);
output.Attributes.Add("alt", Alt);
output.Attributes.Add("src",
$"data:image/png;base64,{Convert.ToBase64String(ms.ToArray())}");
}
}
TagHelper new version using ImageSharp - almost working but not exactly (bottom barcode)
public override void Process(TagHelperContext context, TagHelperOutput output)
{
var margin = 0;
var barcodeWriter = new ZXing.ImageSharp.BarcodeWriter<SixLabors.ImageSharp.PixelFormats.La32>
{
Format = ZXing.BarcodeFormat.PDF_417,
Options = new ZXing.Common.EncodingOptions
{
Height = this.Height > 80 ? this.Height : 80,
Width = this.Width > 400 ? this.Width : 400,
Margin = margin
}
};
var image = barcodeWriter.Write(QRCodeContent);
output.TagName = "img";
output.Attributes.Clear();
output.Attributes.Add("width", Width);
output.Attributes.Add("height", Height);
output.Attributes.Add("alt", Alt);
output.Attributes.Add("src", $"{image.ToBase64String(PngFormat.Instance)}");
}
The issue is as mentioned the 2nd barcode is very slightly different at the end seems to extend the last bar.
What am I missing?
That is a bug in the renderer implementation of the ZXing.Net binding to ImageSharp.
https://github.com/micjahn/ZXing.Net/issues/422
It is fixed in the newest nuget package of the bindings.
https://www.nuget.org/packages/ZXing.Net.Bindings.ImageSharp/
https://www.nuget.org/packages/ZXing.Net.Bindings.ImageSharp.V2/
I tried to add the svg image which contains opacity=0 area into QTextureMaterial on QPlaneMesh, but it shows that the Plane's background is always in gray.
I want that the plane can cantain my image and penetrate to other object in opacity=0 area.
The svg file like https://image.flaticon.com/icons/svg/3154/3154348.svg .
code:
// Background
Qt3DCore::QEntity *planeEntity = new Qt3DCore::QEntity(rootEntity);
Qt3DExtras::QPlaneMesh *planeMesh = new Qt3DExtras::QPlaneMesh(planeEntity);
planeMesh->setHeight(2);
planeMesh->setWidth(2);
Qt3DExtras::QTextureMaterial *planeMaterial = new Qt3DExtras::QTextureMaterial(planeEntity);
Qt3DRender::QTexture2D *planeTexture = new Qt3DRender::QTexture2D(planeMaterial);
FlippedTextureImage *planeTextureImage = new FlippedTextureImage(planeTexture);
planeTextureImage->setSize(QSize(3507, 3000));
planeTexture->addTextureImage(planeTextureImage);
planeMaterial->setTexture(planeTexture);
Qt3DCore::QTransform *planeTransform = new Qt3DCore::QTransform(planeEntity);
planeTransform->setRotationX(90);
planeTransform->setTranslation(QVector3D(0, 0, 0));
Qt3DExtras::QPhongAlphaMaterial *pam2 = new Qt3DExtras::QPhongAlphaMaterial(planeEntity);
pam2->setAlpha(0);
planeEntity->addComponent(planeMesh);
planeEntity->addComponent(pam2);
planeEntity->addComponent(planeMaterial);
planeEntity->addComponent(planeTransform);
class FlippedTextureImage : public Qt3DRender::QPaintedTextureImage
{
public:
FlippedTextureImage(Qt3DCore::QNode *parent = Q_NULLPTR):Qt3DRender::QPaintedTextureImage(parent) {}
void paint(QPainter *painter) override {
QSvgRenderer renderer(QString(qApp->applicationDirPath() + "/gift.svg"));
QImage image(3000, 3000, QImage::Format_RGBA64); // 512x512 RGBA
image.fill(0x00ffffff); // white background
QPainter painter2(&image);
renderer.render(&painter2);
painter->drawImage(0, 0, image);
}
};
and run code like this
QTextureMaterial doesn't support transparency in the textures.
Check out my answer to this question to see how to implement transparency in textures yourself. There is not out-of-the-box solution in Qt3D.
I have a code which converts byte[] to image but my code always writes in Landscape mode even original image was Portrait. How can I detect original image's Page Orientation and write new Image with this properties? Any suggestions?
public void SendFax(byte[] file, string fileName)
{
try
{
MemoryStream ms = new MemoryStream(file);
Image imgSave = Image.FromStream(ms);
Bitmap bmSave = new Bitmap(imgSave);
Bitmap bmTemp = new Bitmap(bmSave);
Graphics grSave = Graphics.FromImage(bmTemp);
grSave.DrawImage(imgSave, 0, 0, imgSave.Width, imgSave.Height)
//Save Image to physical path
bmTemp.Save("C:/..." + fileName);
imgSave.Dispose();
bmSave.Dispose();
bmTemp.Dispose();
grSave.Dispose();
}
catch (Exception ex)
{
throw ex;
}
}
Try with this. Check for img height and width and based on the comparison decide portrait/landscape
int srcWidth = image.Width;
int srcHeight = image.Height;
int thumbWidth = width;
int thumbHeight;
Bitmap bmp;
if (srcHeight > srcWidth)
{
thumbHeight = (srcHeight / srcWidth) * thumbWidth;
bmp = new Bitmap(thumbWidth, thumbHeight);
}
else
{
thumbHeight = thumbWidth;
thumbWidth = (srcWidth / srcHeight) * thumbHeight;
bmp = new Bitmap(thumbWidth, thumbHeight);
}
I'm creating many colour variations of an image using Core Graphics. I need to create about 320 in total but gradually, the memory usage of the app keeps increasing until it crashes. From Instruments, I see that more CGImage objects are being created and stay alive. I want to release them because I store the images to the cache directory in PNG format.
I have searched through all other solutions I could find without success. Any help is appreciated. Thanks.
Here's the main part:
+(UIImage *)tintedImageFromImage:(UIImage *)sourceImage colour:(UIColor *)color intensity:(float)intensity {
if (UIGraphicsBeginImageContextWithOptions != NULL) {
UIGraphicsBeginImageContextWithOptions(sourceImage.size, NO, 0.0);
} else {
UIGraphicsBeginImageContext(sourceImage.size);
}
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect rect = CGRectMake(0, 0, sourceImage.size.width, sourceImage.size.height);
// draw alpha-mask
CGContextSetBlendMode(context, kCGBlendModeNormal);
CGContextDrawImage(context, rect, sourceImage.CGImage);
// draw tint color, preserving alpha values of original image
CGContextSetBlendMode(context, kCGBlendModeSourceIn);
[color setFill];
CGContextFillRect(context, rect);
//Set the original greyscale template as the overlay of the new image
sourceImage = [self verticallyFlipImage:sourceImage];
[sourceImage drawInRect:CGRectMake(0,0, sourceImage.size.width,sourceImage.size.height) blendMode:kCGBlendModeMultiply alpha:intensity];
UIImage *colouredImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
colouredImage = [self verticallyFlipImage:colouredImage];
return colouredImage;
}
this is used to flip the image:
+(UIImage *)verticallyFlipImage:(UIImage *)originalImage {
UIImageView *tempImageView = [[UIImageView alloc] initWithImage:originalImage];
UIGraphicsBeginImageContext(tempImageView.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGAffineTransform flipVertical = CGAffineTransformMake(1, 0, 0, -1, 0, tempImageView.frame.size.height);
CGContextConcatCTM(context, flipVertical);
[tempImageView.layer renderInContext:context];
UIImage *flippedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return flippedImage;
}
Add to verticallyFlipImage the line tempImageView.image = nil; in order to make the image view release the image. This solves the problem.
I wanted to know if we can resize an image. Suppose if we want to draw an image of 200x200 actual size with a size of 100 x 100 size on our blackberry screen.
Thanks
You can do this pretty simply using the EncodedImage.scaleImage32() method. You'll need to provide it with the factors by which you want to scale the width and height (as a Fixed32).
Here's some sample code which determines the scale factor for the width and height by dividing the original image size by the desired size, using RIM's Fixed32 class.
public static EncodedImage resizeImage(EncodedImage image, int newWidth, int newHeight) {
int scaleFactorX = Fixed32.div(Fixed32.toFP(image.getWidth()), Fixed32.toFP(newWidth));
int scaleFactorY = Fixed32.div(Fixed32.toFP(image.getHeight()), Fixed32.toFP(newHeight));
return image.scaleImage32(scaleFactorX, scaleFactorY);
}
If you're lucky enough to be developer for OS 5.0, Marc posted a link to the new APIs that are a lot clearer and more versatile than the one I described above. For example:
public static Bitmap resizeImage(Bitmap originalImage, int newWidth, int newHeight) {
Bitmap newImage = new Bitmap(newWidth, newHeight);
originalImage.scaleInto(newImage, Bitmap.FILTER_BILINEAR, Bitmap.SCALE_TO_FILL);
return newImage;
}
(Naturally you can substitute the filter/scaling options based on your needs.)
Just an alternative:
BlackBerry - draw image on the screen
BlackBerry - image 3D transform
I'm not a Blackberry programmer, but I believe some of these links will help you out:
Image Resizing Article
Resizing a Bitmap on the Blackberry
Blackberry Image Scaling Question
Keep in mind that the default image scaling done by BlackBerry is quite primitive and generally doesn't look very good. If you are building for 5.0 there is a new API to do much better image scaling using filters such as bilinear or Lanczos.
For BlackBerry JDE 5.0 or later, you can use the scaleInto API.
in this there is two bitmap.temp is holding the old bitmap.In this method you just pass
bitmap ,width,height.it return new bitmap of your choice.
Bitmap ImgResizer(Bitmap bitmap , int width , int height){
Bitmap temp=new Bitmap(width,height);
Bitmap resized_Bitmap = bitmap;
temp.createAlpha(Bitmap.HOURGLASS);
resized_Bitmap.scaleInto(temp , Bitmap.FILTER_LANCZOS);
return temp;
}
Here is the function or you can say method to resize image, use it as you want :
int olddWidth;
int olddHeight;
int dispplayWidth;
int dispplayHeight;
EncodedImage ei2 = EncodedImage.getEncodedImageResource("add2.png");
olddWidth = ei2.getWidth();
olddHeight = ei2.getHeight();
dispplayWidth = 40;\\here pass the width u want in pixels
dispplayHeight = 80;\\here pass the height u want in pixels again
int numeerator = net.rim.device.api.math.Fixed32.toFP(olddWidth);
int denoominator = net.rim.device.api.math.Fixed32.toFP(dispplayWidth);
int widtthScale = net.rim.device.api.math.Fixed32.div(numeerator, denoominator);
numeerator = net.rim.device.api.math.Fixed32.toFP(olddHeight);
denoominator = net.rim.device.api.math.Fixed32.toFP(dispplayHeight);
int heighhtScale = net.rim.device.api.math.Fixed32.div(numeerator, denoominator);
EncodedImage newEi2 = ei2.scaleImage32(widtthScale, heighhtScale);
Bitmap _add =newEi2.getBitmap();
I am posting this answers for newbie in Blackberry Application development. Below code is for processing Bitmap images from URL and Resizing them without loass of Aspect Ratio :
public static Bitmap imageFromServer(String url)
{
Bitmap bitmp = null;
try{
HttpConnection fcon = (HttpConnection)Connector.open(url);
int rc = fcon.getResponseCode();
if(rc!=HttpConnection.HTTP_OK)
{
throw new IOException("Http Response Code : " + rc);
}
InputStream httpInput = fcon.openDataInputStream();
InputStream inp = httpInput;
byte[] b = IOUtilities.streamToBytes(inp);
EncodedImage img = EncodedImage.createEncodedImage(b, 0, b.length);
bitmp = resizeImage(img.getBitmap(), 100, 100);
}
catch(Exception e)
{
Dialog.alert("Exception : " + e.getMessage());
}
return bitmp;
}
public static Bitmap resizeImage(Bitmap originalImg, int newWidth, int newHeight)
{
Bitmap scaledImage = new Bitmap(newWidth, newHeight);
originalImg.scaleInto(scaledImage, Bitmap.FILTER_BILINEAR, Bitmap.SCALE_TO_FIT);
return scaledImage;
}
The Method resizeImage is called inside the method imageFromServer(String url).
1) the image from server is processed using EncodedImage img.
2) Bitmap bitmp = resizeImage(img.getBitmap(), 100, 100);
parameters are passed to resizeImage() and the return value from resizeImage() is set to Bitmap bitmp.