WP7 zxing scan not reliable - windows-phone-7

I've printed a few short qr-codes (like "HAEB16653") on a page using this algorythm:
private void CreateQRCodeFile(int size, string filename, string codecontent)
{
QRCodeWriter writer = new QRCodeWriter();
com.google.zxing.common.ByteMatrix matrix;
matrix = writer.encode(codecontent, BarcodeFormat.QR_CODE, size, size, null);
Bitmap img = new Bitmap(size, size);
Color Color = Color.FromArgb(0, 0, 0);
for (int y = 0; y < matrix.Height; ++y)
{
for (int x = 0; x < matrix.Width; ++x)
{
Color pixelColor = img.GetPixel(x, y);
//Find the colour of the dot
if (matrix.get_Renamed(x, y) == -1)
{
img.SetPixel(x, y, Color.White);
}
else
{
img.SetPixel(x, y, Color.Black);
}
}
}
img.Save(filename, ImageFormat.Png);
}
The printed barcodes work very well and fast with the integrated WP7 bing scan&search.
When I try to scan the very same printed qrcodes with Stéphanie Hertrichs sample app, scanning is very slow, most do not scan at all, or will only be recognized when I slowly rotate the camera around.
How do I get my scanning to be as reliable as the integrated barcode recognition? I only need to scan QrCodes, so I disabled all the others, still it does not work most of the time.
Is there maybe some other barcode scanning library which is working better?

The silverlight port in Stéphanie Hertrichs sample app is very old. It seems to me that the project at codeplex isn't maintained anymore since more then 1 year. You should try one of the newer and maintained ports like ZXing.Net

zxing works very well -- just try it on Android. I would not be surprised if it is what powers the Bing search.
The problems are likely in the port. Any non-Java port is at best old and incomplete. I also can't speak to the efficiency of the approach used in the sample you are looking at. For example, is it really binarizing the image from the APIs correctly? Also make sure it is not using TRY_HARDER mode.

There is no objective answer to this question...
My personal opinion is that the ZXing lib that you tried (Stéphanie Hertrichs sample app) is the best you can get. As far as I know it is used on the other plattforms, too (e.g. Android).
As I tested the lib a few months ago, I had the impression it worked very reliable and quick, but it may be that you had other circumstances (lighting, camera, angle, etc...)

Related

rust imgui, how do you set it up?

I am trying to set up rust imgui for a custom renderer I am porting to rust.
I am stuck on two fronts, getting the peripheral callbacks, and the rendering.
In C++ the setup was farily simple
ImGuiContext* InitImgui(ModuleStorage::ModuleStorage& module, NECore::Gallery& gallery)
{
ImGuiContext* imgui_context = ImGui::CreateContext();
ImGuiIO& io = ImGui::GetIO();
unsigned char* pixels;
int width, height;
io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);
CpuImage font_image(pixels, width, height, 4);
uint font_id = gallery.StoreImage<CpuImage::GetImageData>(
font_image, "__ImguiFont", NECore::ImageFormat::R8G8B8A8_UNORM);
io.Fonts->SetTexID((ImTextureID)(intptr_t)font_id);
ImGui_ImplGlfw_InitForVulkan(module.GetWindow().GetGLFWWindow(), true);
imgui_shader = module.AddShader(
{"./CommonShaders/imgui.vert",
"./CommonShaders/imgui.frag"});
return imgui_context;
}
30 lines of code and we have the initialization done.
Well some issues in rust, io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); does not exist. I assume the equivalent is let font = fonts.build_rgba32_texture();
Assuming that's the case the next issue is setting the texture id, which I cannot find anywhere in the docs or the source code.
io.Fonts->SetTexID((ImTextureID)(intptr_t)font_id);
That function does not exist in the rust bindings. And ImGui_ImplGlfw_InitForVulkan is no where to be found either.
The examples https://github.com/imgui-rs/imgui-rs/blob/main/imgui-examples/examples/support/mod.rs
Seem to be using pre existen renderers and do not do a good job of showing how to integrate the tool onto an existing renderer other than the ones the author chose, which is baffling, one of the biggest selling points of imgui is how simple it is to integrate in pre-existing codebases.
I am at a loss, hwo do you bootstrap the library in rust?

How can I randomize a video to play after another by pressing a key on Processing?

I'm quite new to Processing.
I'm trying to make Processing randomly play a video after I clear the screen by mouseclick, so I create an array that contain 3 videos and play one at a time.
Holding 'Spacebar' will play a video and release it will stop the video. Mouseclick will clear the screen to an image. The question is how can it randomize to another video if I press spacebar again after clear the screen.
I've been searching all over the internet but couldn't find any solution for my coding or if my logic is wrong, please help me.
Here's my code.
int value = 0;
PImage photo;
import processing.video.*;
int n = 3; //number of videos
float vidN = random(0, n+1);
int x = int (vidN);
Movie[] video = new Movie[3];
//int rand = 0;
int index = 0;
void setup() {
size(800, 500);
frameRate(30);
video = new Movie[3];
video[0] = new Movie (this, "01.mp4");
video[1] = new Movie (this, "02.mp4");
video[2] = new Movie (this, "03.mp4");
photo = loadImage("1.jpg");
}
void draw() {
}
void movieEvent(Movie video) {
video.read();
}
void keyPressed() {
if (key == ' ') {
image(video[x], 0, 0);
video[x].play();
}
}
void mouseClicked() {
if (value == 0) {
video[x].jump(0);
video[x].stop();
background(0);
image(photo, 0, 0);
}
}
You have this bit of logic in your code which picks a random integer:
float vidN = random(0, n+1);
int x = int (vidN);
In theory, if you want to randomise to another video when the spacebar is pressed again you can re-use this bit of logic:
void keyPressed() {
if (key == ' ') {
x = int(random(n+1));
image(video[x], 0, 0);
video[x].play();
}
}
(Above I've used shorthand of the two lines declaring vidN and x, but the logic is the same. If the logic is harder to follow since two operations on the same line (picking a random float between 0,n+1 and rounding down to an integer value), feel free to expand back to two lines: readability is more important).
As side notes, these bit of logic look a bit off:
the if (value == 0) condition will always be true since value never changes, making both value and the condition redundant. (Perhaps you plan to use for something else later ? If so, you could save separate sketches, but start with the simplest version and exclude anything you don't need, otherwise, in general, remove any bit of code you don't need. It will be easier to read, follow and change.)
Currently your logic says that whenever you click current video resets to the start and stops playing and when you hit the spacebar. Once you add the logic to randomise the video that the most recent frame of the current video (just randomised) will display (image(video[x], 0, 0);), then that video will play. Unless you click to stop the current video, previously started videos (via play()) will play in the background (e.g. if they have audio you'll hear them in the background even if you only see one static frame from the last time space was pressed).
Maybe this is the behaviour you want ? You've explained a localised section of what you want to achieve, but not overall what the whole of the program you posted should do. That would help others provide suggestions regarding logic.
In general, try to break the problem down to simple steps that you can test in isolation. Once you've found a solid solution for each part, you can add each part into a main sketch one at a time, testing each time you add something. (This way if something goes wrong it's easy to isolate/fix).
Kevin Workman's How To Program is a great article on this.
As a mental excercise it will help to read through the code line by line and imagine what it might do. Then run it and see if the code behaves as you predicted/intended. Slowly and surely this will get better and better. Have fun learning!

Check if exact image in exact location is on screen

I am looking to create a program in Visual Studio (C#) which scans the screen for an exact image in an exact location of the screen. I have seen many discussions which involve algorithms to find a "close" image, but mine will be 100% exact; location, size and all.
I have obtained a png from a section of my screen [Image 1] using this code:
private void button1_Click(object sender, EventArgs e)
{
//Create a new bitmap.
var bmpScreenshot = new Bitmap(Screen.PrimaryScreen.Bounds.Width,
Screen.PrimaryScreen.Bounds.Height);
// Create a graphics object from the bitmap.
var gfxScreenshot = Graphics.FromImage(bmpScreenshot);
// Take the screenshot from the upper left corner to the right bottom corner.
gfxScreenshot.CopyFromScreen(1555, 950,
1700, 1010,
Screen.PrimaryScreen.Bounds.Size,
CopyPixelOperation.SourceCopy);
// Save the screenshot to the specified path that the user has chosen.
bmpScreenshot.Save("Screenshot.png");
}
So, basically here is the flowchart of my program on how I want to move forward:
1) create the master png using the above code
2) run loop:
create same screenshot using the same procedure as the master png
compare master png to new screenshot png and if:match then move on otherwise reiterate loop.
I am very new to programming, but I don't believe this is beyond me, given a little guidance. I have written fairly complicated (in my opinion) VBA and Matlab programs. Any help is greatly appreciated.
Thank You,
Sloan
Digging around a bit through Microsoft's documentation, I came up with a rough function that would do something similar to what you want.
https://msdn.microsoft.com/en-us/library/hh191601.aspx
This function offers the chance of getting stuck in an endless loop, so you might consider calling it with a timeout from your main. See here for info on synchronous methods with timeouts:
Monitoring a synchronous method for timeout
From your main, all you'd have to do is see if it returns true.
static int Main(string[] args)
{
if (ImageInLocation(left, right, top, bottom)) {
// do other things
}
return 0;
}
The only thing I'm not entirely sure on is how strict you can be with the ColorDifference. Even if the images are identical, any pixel difference with an entirely non-tolerant ColorDifference will come up false. If you know it should work and it's not, perhaps consider increasing the tolerance. Here's some more info on that:
https://msdn.microsoft.com/en-us/library/microsoft.visualstudio.testtools.uitesting.colordifference.aspx
public bool ImageInLocation(int left, int right, int top, int bottom) {
bool image_found = false;
var masterImage = Image.FromFile("path_to_master");
while (!image_found) {
// screenshot code above, output to "path_to/Screenshot.jpg"
var compImage = Image.FromFile("path_to/Screenshot.jpg");
// note, all zeroes may not be tolerant enough
var color_diff = new ColorDifference(0, 0, 0, 0);
Image diffImage;
image_found = ImageComparer.Compare(masterImage, compImage, color_diff, out diffImage);
}
return true;
}
Good luck! Welcome to the programming community.
Also, if anyone has any suggestions/changes, feel free to edit this. Happy imaging, friends!

FMOD Ex dropping sounds, eventually going silent

I'm attempting to port an old open-source FMOD 3 game (Candy Crisis) to the latest version of FMOD Ex 4 on OS X. Its sound needs are very simple—it plays WAVs, sometimes changing their frequency or speaker mix, and also plays MOD tracker music, sometimes changing the speed. I'm finding that the game works fine at first, but over the course of a few minutes, it starts truncating sounds early, then the music loses channels and eventually stops, then over time all sound ceases. I can cause the problem to reproduce more quickly if I lower the number of channels available to FMOD.
I can get the truncated/missing sounds issue to occur even if I never play a music file, but music definitely seems to make things worse. I have also tried commenting out the code which adjusts the sound frequency and speaker mix, and that was not the issue.
I am calling update() every frame.
Here's the entirety of my interactions with FMOD to play WAVs:
void InitSound( void )
{
FMOD_RESULT result = FMOD::System_Create(&g_fmod);
FMOD_ERRCHECK(result);
unsigned int version;
result = g_fmod->getVersion(&version);
FMOD_ERRCHECK(result);
if (version < FMOD_VERSION)
{
printf("Error! You are using an old version of FMOD %08x. This program requires %08x\n", version, FMOD_VERSION);
abort();
}
result = g_fmod->init(8 /* was originally 64, but 8 repros the issue faster */, FMOD_INIT_NORMAL, 0);
FMOD_ERRCHECK(result);
for (int index=0; index<kNumSounds; index++)
{
result = g_fmod->createSound(QuickResourceName("snd", index+128, ".wav"), FMOD_DEFAULT, 0, &s_sound[index]);
FMOD_ERRCHECK(result);
}
}
void PlayMono( short which )
{
if (soundOn)
{
FMOD_RESULT result = g_fmod->playSound(FMOD_CHANNEL_FREE, s_sound[which], false, NULL);
FMOD_ERRCHECK(result);
}
}
void PlayStereoFrequency( short player, short which, short freq )
{
if (soundOn)
{
FMOD::Channel* channel = NULL;
FMOD_RESULT result = g_fmod->playSound(FMOD_CHANNEL_FREE, s_sound[which], true, &channel);
FMOD_ERRCHECK(result);
result = channel->setSpeakerMix(player, 1.0f - player, 0, 0, 0, 0, 0, 0);
FMOD_ERRCHECK(result);
float channelFrequency;
result = s_sound[which]->getDefaults(&channelFrequency, NULL, NULL, NULL);
FMOD_ERRCHECK(result);
result = channel->setFrequency((channelFrequency * (16 + freq)) / 16);
FMOD_ERRCHECK(result);
result = channel->setPaused(false);
FMOD_ERRCHECK(result);
}
}
void UpdateSound()
{
g_fmod->update();
}
And here's how I play MODs.
void ChooseMusic( short which )
{
if( musicSelection >= 0 && musicSelection <= k_songs )
{
s_musicChannel->stop();
s_musicChannel = NULL;
s_musicModule->release();
s_musicModule = NULL;
musicSelection = -1;
}
if (which >= 0 && which <= k_songs)
{
FMOD_RESULT result = g_fmod->createSound(QuickResourceName("mod", which+128, ""), FMOD_DEFAULT, 0, &s_musicModule);
FMOD_ERRCHECK(result);
result = g_fmod->playSound(FMOD_CHANNEL_FREE, s_musicModule, true, &s_musicChannel);
FMOD_ERRCHECK(result);
EnableMusic(musicOn);
s_musicModule->setLoopCount(-1);
s_musicChannel->setPaused(false);
musicSelection = which;
s_musicPaused = 0;
}
}
If someone wants to experiment with this, let me know and I'll upload the project somewhere. My gut feeling is that FMOD is busted but I'd love to be proven wrong.
Sounds like your music needs to be set as higher priority than your other sounds. Remember, lower numbers are more important. I think you can just set the priority on the channel.
Every time I play the following WAV, FMOD loses one channel permanently. I am able to reproduce this channel-losing behavior in the "playsound" example if I replace the existing jaguar.wav with my file.
https://drive.google.com/file/d/0B1eDRY8sV_a9SXMyNktXbWZOYWs/view?usp=sharing
I contacted Firelight and got this response. Apparently WAVs can include a looping command! I had no idea.
Hello John,
I've taken a look at the two files you have provided. Both files end
with a 2 sample infinite loop region.
FMOD 4 (and FMOD 5 for that matter) will see the loop region in the
file and automatically enable FMOD_LOOP_NORMAL if you haven't
specified any loop mode. Assuming you want one-shot behavior just pass
in FMOD_LOOP_OFF when you create the sound.
Kind regards, Mathew Block | Senior Platform Engineer
Technically this behavior contradicts the documented behavior of FMOD_DEFAULT (which is specified to imply FMOD_LOOP_OFF) so they are planning to improve the documentation here.
Based on the wave sample you supplied, FMOD is behaving correctly as it appears you've figured out. The sample has a loop that is honored by FMOD and the last samples are simply repeated forever. While useless, this is correct and the variance in the samples is so slight as to not be audible. While not part of the original spec for wave format, extended information was added later to support meta data such as author, title, comments and multiple loop points.
Your best bet is to examine all your source assets for those that contain loop information. Simply playing all sounds without loop information is probably not the best workaround. Some loops may be intentional. Those that are will have code that stops them. Typically, in a game, the entire waveform is looped when looping is desired. You can then write or use a tool that will strip the loop information. If you do write your own tool, I'd recommend resampling the audio to the native output sampling rate of the hardware. You'd need to insure your resampler was sample accurate (no time shift) and did not introduce noise.
Historically, some game systems had a section at the end of the sound with silence and a loop point set on this region. The short reason for this was to reduce popping that might occur at the end of a sound in a hardware audio channel.
Curiosly, the last 16 samples of your .wav look like garbage and I'm wondering if the .wav assets you're using were converted from a source meant for a game console and that's where the bogus loop information came from as well.
This would have been a comment but my lowly rep does not allow it.

ExtCreatePen and Windows 7 GDI

I created DIBPATTERN pens with ExtCreatePen API for custom pattern pens.
It sucessfully draws desired lines on Windows XP,
But on Windows 7 (x64 for my case), it does not draw any lines; no changes on screen.
(Other simply created pens, for example CreatePen(PS_DOT,1,0), are working.)
I found that calling SetROP2(hdc, R2_XORPEN) makes the following line-drawing API calls draw something but with XOR operation. I don't want XOR drawing.
Here is my code to create the pen. It has no problem on Windows XP:
LOGBRUSH lb;
lb.lbStyle = BS_DIBPATTERN;
lb.lbColor = DIB_RGB_COLORS;
int cb = sizeof(BITMAPINFOHEADER) + sizeof(RGBQUAD) * 2 + 8*4;
HGLOBAL hg = GlobalAlloc(GMEM_MOVEABLE, cb);
BITMAPINFO* pbmi = (BITMAPINFO*) GlobalLock(hg);
ZeroMemory(pbmi, cb);
pbmi->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
pbmi->bmiHeader.biWidth = 8;
pbmi->bmiHeader.biHeight = 8;
pbmi->bmiHeader.biPlanes = 1;
pbmi->bmiHeader.biBitCount = 1;
pbmi->bmiHeader.biCompression = BI_RGB;
pbmi->bmiHeader.biSizeImage = 8;
pbmi->bmiHeader.biClrUsed = 2;
pbmi->bmiHeader.biClrImportant = 2;
pbmi->bmiColors[1].rgbBlue =
pbmi->bmiColors[1].rgbGreen =
pbmi->bmiColors[1].rgbRed = 0xFF;
DWORD* p = (DWORD*) &pbmi->bmiColors[2];
for(int k=0; k<8; k++) *p++ = patterns[k];
GlobalUnlock(hg);
lb.lbHatch = (LONG) hg;
s_aSelectionPens[i] = ExtCreatePen(PS_GEOMETRIC, 1, &lb, 0, NULL);
ASSERT(s_aSelectionPens[i]); // success on both XP and Win7
GlobalFree(hg);
Is it bug only on my PC? Please check this problem.
Thank you.
This is a known bug with the Windows 7 GDI, though good luck getting Microsoft to acknowledge it.
http://social.technet.microsoft.com/Forums/en-US/w7itproappcompat/thread/a70ab0d5-e404-4e5e-b510-892b0094caa3
-Noel
I will admit, I was dubious as first, but I compiled and ran your program, and it does indeed fail to draw the second line on Windows 7, buy only in aero mode
By switching to Windows basic or classic mode, all four lines are drawn, as expected.
I can only assume that this is some kind of bad interaction with your custom pen and the new way aero mode implements GDI calls. This seems like it might be a Microsoft bug, perhaps you can post this question on one of their message boards?
So you are creating an 8x8 black/white (monochrome) bitmap as a DIB, and then using that to create a pen. I see nothing wrong with this code. this definitely looks like a windows bug, but there may be a workaround.
Try setting
pbmi->bmiHeader.biClrUsed = 0;
pbmi->bmiHeader.biClrImportant = 0;
In this context, setting the values to 0 should mean the same thing as setting them to 2, but 0 is more standard behavior for situations where you have are using the full palette. You still need two entries in your palette, 0 just means "full size based on biBitCount".
Also, each palette entrie is a RGBQUAD, which means there is room for alpha, and your alpha is set to 0, which should be ignored, but maybe it isn't. so try setting the high byte of your two palette entries to 0xFF or 0x80.
Finally, it's possible that your palette is being ignored entirely, and Windows is using the BkMode, BkColor and TextColor of the destination DC for everything, so you need to make sure that they are set to values that you can see.
My guess is that this has something to do with alpha transparency, since GDI ignores alpha entirely, but Aero doesn't.

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