rose_image.C

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/// \file
/// \ingroup tutorial_image
/// \notebook
/// Display image in a new canvas and pad.
///
/// \macro_image
/// \macro_code
///
/// \author Valeriy Onuchin
 
#include "TImage.h"
#include "TCanvas.h"
#include "TArrayD.h"
#include "TROOT.h"
#include "TColor.h"
#include "TAttImage.h"
#include "TEnv.h"
 
TCanvas *c1;
 
void rose_image()
{
   TString dir = TROOT::GetTutorialDir();
 
   TImage *img = TImage::Open(dir + "/visualisation/image/rose512.jpg");
 
   if (!img) {
      printf("Could not create an image... exit\n");
      return;
   }
 
   img->SetConstRatio(false);
   img->SetImageQuality(TAttImage::kImgBest);
 
   TString bc = "BlackChancery.ttf";
   TString ar = "arial.ttf";
 
   // draw text over image with funny font
   img->DrawText(120, 160, "Hello World!", 32, gROOT->GetColor(4)->AsHexString(), bc, TImage::kShadeBelow);
 
   // draw text over image with foreground specified by pixmap
   img->DrawText(250, 350, "goodbye cruel world ...", 24, nullptr, ar, TImage::kPlain, dir + "/image/fore.xpm");
 
   TImage *img2 = TImage::Open(dir + "/image/mditestbg.xpm");
 
   // tile image
   img2->Tile(img->GetWidth(), img->GetHeight());
 
   c1 = new TCanvas("rose512", "examples of image manipulations", 760, 900);
   c1->Divide(2, 3);
   c1->cd(1);
   img->Draw("xxx");
   img->SetEditable(kTRUE);
 
   c1->cd(2);
   // averaging with mditestbg.xpm image
   TImage *img3 = (TImage *)img->Clone("img3");
   img3->Merge(img2, "allanon");
   img3->Draw();
 
   // contrasting (tint with itself)
   c1->cd(3);
   TImage *img4 = (TImage *)img->Clone("img4");
   img4->Merge(img4, "tint");
 
   // draw filled rectangle with magenta color
   img4->FillRectangle("#FF00FF", 20, 220, 40, 40);
 
   // Render multipoint alpha-blended gradient (R->G->B)
   img4->Gradient(0, "#FF0000 #00FF00 #220000FF", nullptr, 50, 50, 100, 100);
 
   // draw semi-transparent 3D button
   img4->Bevel(300, 20, 160, 40, "#ffffffff", "#fe000000", 3, false);
   img4->DrawLine(10, 100, 100, 10, "#0000ff", 4);
   img4->Draw();
 
   // vectorize image. Reduce palette to 256 colors
   c1->cd(4);
   TImage *img5 = (TImage *)img->Clone("img5");
   img5->Vectorize(256);
   img5->Draw();
 
   // quantization of the image
   c1->cd(5);
   TImage *img6 = (TImage *)img->Clone("img6");
   TImagePalette *pal = (TImagePalette *)&img5->GetPalette();
   TArrayD *arr = img6->GetArray(50, 40, pal);
   img6->SetImage(arr->GetArray(), 50, 40, pal);
   delete arr; // one must delete array
   img6->Draw();
 
   // HSV adjustment (convert red to yellow)
   c1->cd(6);
   TImage *img7 = (TImage *)img->Clone("img7");
   img7->HSV(0, 40, 40);
   img7->Draw();
}