#stb_image is giving me a "not a PNG" error even though I'm trying to read .jpeg

6 messages · Page 1 of 1 (latest)

tidal portal
# 
#include <iostream>

extern "C" {
    #define STB_IMAGE_IMPLEMENTATION
    #define STBI_FAILURE_USERMSG
    #define STB
    #include "stb_image.h"
    #define STB_IMAGE_WRITE_IMPLEMENTATION
    #include "stb_image_write.h"
}

#define print(x) std::cout << (x) << std::endl

std::string imageToASCII(const char filename[], int charHeight = 30, int charWidth = 60) {
  const char brightnessChars[] = "@$%#?{!<+=,-. ";
  
  int width, height, channel;
  uint8_t *data = stbi_load(filename, &width, &height, &channel, 0);
  if (stbi_failure_reason()) {
    throw std::invalid_argument(stbi_failure_reason());
    // My code breaks here ^^^^^^^^^^^^^^^^^^^^^^^^^
  }

  // Begin with calculating the image and char ratio so we can fit the chars appropriately
  float imageRatio = static_cast<float>(width) / height;
  float charRatio = static_cast<float>(charWidth) / charHeight;

  // Then scale the ascii grid accordingly
  if (imageRatio < charRatio) {
    charWidth = round(charHeight * imageRatio);
  } else if (imageRatio > charRatio) {
    charHeight = round(charWidth / imageRatio);
  }

  print(stbi_write_jpg("bwdemo.jpg", height/channel, width/channel, 1, grayscaleImage(data, height, width, channel), 0));
  
  stbi_image_free(data);
}

int main()
{
  std::string filename = "demo.jpeg";
  imageToASCII(filename.c_str());
}
image.png
dim hillBOT
#

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undone silo
#

Instead of checking if stbi_failure_reason() returns a non-null ptr, check the data variable

tidal portal
#

That was way easier than I thought. Thanks so much

dim hillBOT
#

Thank you and let us know if you have any more questions!

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undone silo
#

No problem. The way stbi image does error handling is a bit wonky