Merge pull request #2239 from socram8888/waveshare-gd

Add image cropping and scaling

CHANGELOG.md

@@ -9,6 +9,7 @@ This project uses the changelog in accordance with [keepchangelog](http://keepac
  - Fixed `lf pyramid sim` - wrong parameter handling (@iceman1001)
  - Fixed bootloader - Ignore jitters when pressing the button (@wh201906)
  - Changed `hf waveshare` - image loading and processing is now done using [GDlib](https://github.com/libgd/libgd) (@socram8888)
+ - Changed `hf waveshare` - image is automatically scaled and cropped to match panel size (@socram8888)
 
 ## [Steamboat Willie.4.17768][2024-01-03]
  - Changed `mem spiffs dump -t` - now supports downloading direct into trace buffer (@hazardousvoltage)

client/src/cmdhfwaveshare.c

@@ -631,14 +631,13 @@ static int CmdHF14AWSLoad(const char *Cmd) {
         return PM3_EFILE;
     }
 
-    if (
-        gdImageSX(rgb_img) != models[model_nr].width ||
-        gdImageSY(rgb_img) != models[model_nr].height
-    ) {
-        PrintAndLogEx(WARNING, "Image size does not match panel size");
+    gdImagePtr scaled_img = img_crop_to_fit(rgb_img, models[model_nr].width, models[model_nr].height);
+    if (scaled_img == NULL) {
+        PrintAndLogEx(WARNING, "Failed to scale input image");
         gdImageDestroy(rgb_img);
         return PM3_EFILE;
     }
+    gdImageDestroy(rgb_img);
 
     int pal_len = 2;
     int pal[3];
@@ -649,8 +648,8 @@ static int CmdHF14AWSLoad(const char *Cmd) {
         pal[2] = gdTrueColorAlpha(0xFF, 0x00, 0x00, 0); // Red
     }
 
-    gdImagePtr pal_img = img_palettize(rgb_img, pal, pal_len);
-    gdImageDestroy(rgb_img);
+    gdImagePtr pal_img = img_palettize(scaled_img, pal, pal_len);
+    gdImageDestroy(scaled_img);
 
     if (!pal_img) {
         PrintAndLogEx(WARNING, "Could not convert image");
@@ -662,7 +661,7 @@ static int CmdHF14AWSLoad(const char *Cmd) {
             PrintAndLogEx(INFO, "Save converted image to " _YELLOW_("%s"), outfile);
             gdImageDestroy(pal_img);
             return PM3_SUCCESS;
-		} else {
+        } else {
             PrintAndLogEx(WARNING, "Could not save converted image", outfile);
             gdImageDestroy(pal_img);
             return PM3_EFILE;

client/src/imgutils.c

@@ -33,14 +33,6 @@ static inline void cap_comp(int * x) {
     }
 }
 
-/*
- * The following function implements a Floyd-Steinberg in YCbCr color space.
- *
- * Using this colorspace, the Euclidean distance between colors is closer to human perception than
- * in sRGB, which results in a more accurate color rendering.
- *
- * A comparison can be found at https://twitter.com/Socram4x8/status/1733157380097995205/photo/1.
- */
 gdImagePtr img_palettize(gdImagePtr rgb, int * palette, int palette_size) {
     assert(rgb != NULL);
     assert(palette != NULL);
@@ -157,3 +149,58 @@ gdImagePtr img_palettize(gdImagePtr rgb, int * palette, int palette_size) {
     free(pal_ycbcr);
     return res;
 }
+
+gdImagePtr img_crop_to_fit(gdImagePtr orig, int width, int height) {
+    assert(orig != NULL);
+    assert(width >= 1);
+    assert(height >= 1);
+
+    gdImagePtr res;
+    if (gdImageTrueColor(orig)) {
+        res = gdImageCreateTrueColor(width, height);
+    } else {
+        res = gdImageCreate(width, height);
+    }
+
+    if (!res) {
+        return NULL;
+    }
+
+    if (gdImageSY(orig) * width <= gdImageSX(orig) * height) {
+        // Image is wider than expected, so we will crop the left and right sides
+
+        int crop_width = gdImageSY(orig) * width / height;
+        int crop_sx = gdImageSX(orig) / 2 - crop_width / 2;
+        gdImageCopyResampled(
+            res,             // Dest img
+            orig,            // Src image
+            0,               // Dest X
+            0,               // Dest Y
+            crop_sx,         // Src X
+            0,               // Src Y
+            width,           // Dest width
+            height,          // Dest height
+            crop_width,      // Src width
+            gdImageSY(orig)  // Src height
+        );
+    } else {
+        // Image is taller than expected, so we will crop the top and bottom sides
+
+        int crop_height = gdImageSX(orig) * height / width;
+        int crop_sy = gdImageSY(orig) / 2 - crop_height / 2;
+        gdImageCopyResampled(
+            res,             // Dest img
+            orig,            // Src image
+            0,               // Dest X
+            0,               // Dest Y
+            0,               // Src X
+            crop_sy,         // Src Y
+            width,           // Dest width
+            height,          // Dest height
+            gdImageSX(orig), // Src width
+            crop_height      // Src height
+        );
+    }
+
+    return res;
+}

client/src/imgutils.h

@@ -20,6 +20,20 @@
 
 #include <gd.h>
 
+/*
+ * Converts a true color image to a palette image, using Floyd-Steinberg dithering.
+ *
+ * For color matching, this function uses the Euclidean distance between colors in the
+ * YCbCr color space, which yields to better results than using sRGB directly.
+ *
+ * A comparison can be found at https://twitter.com/Socram4x8/status/1733157380097995205/photo/1.
+ */
 gdImagePtr img_palettize(gdImagePtr rgb, int * palette, int palette_size);
 
+/*
+ * This function scales and crops the image to the given size.
+ * Think of "background-size: cover" in CSS.
+ */
+gdImagePtr img_crop_to_fit(gdImagePtr orig, int width, int height);
+
 #endif