feat: add OpenAI gpt-image-1 and gpt-image-1-mini models with new parameters

Add support for OpenAI's new GPT Image models (gpt-image-1 and gpt-image-1-mini)
with all new model-specific parameters according to the official API specification.

Changes:
- Add GPT_IMAGE_1 and GPT_IMAGE_1_MINI to ImageModel enum
- Update default image model from DALL_E_3 to GPT_IMAGE_1_MINI
- Add 6 new gpt-image-1 specific parameters to OpenAiImageRequest:
  * background: transparency control (transparent/opaque/auto)
  * moderation: content moderation level (low/auto)
  * outputCompression: compression level 0-100% for webp/jpeg
  * outputFormat: output format (png/jpeg/webp)
  * partialImages: streaming partial images support (0-3)
  * stream: enable streaming mode
- Update OpenAiImageOptions with new fields, getters/setters, and builder methods
- Update documentation to reflect model-specific parameter support
- Add comprehensive integration tests (OpenAiImageApiIT) with parameterized tests
- Update existing tests to use new default model

Breaking Changes:
- Default image model changed from DALL_E_3 to GPT_IMAGE_1_MINI
- OpenAiImageRequest constructor signature updated with 6 new parameters

Reference: https://platform.openai.com/docs/models
Signed-off-by: Alexandros Pappas <[email protected]>

Author: apappascs

auto-configurations/models/spring-ai-autoconfigure-model-openai/src/main/java/org/springframework/ai/model/openai/autoconfigure/OpenAiImageProperties.java

@@ -37,7 +37,7 @@ public class OpenAiImageProperties extends OpenAiParentProperties {
 
 	private String imagesPath = DEFAULT_IMAGES_PATH;
 
-	public static final String DEFAULT_IMAGE_MODEL = OpenAiImageApi.ImageModel.DALL_E_3.getValue();
+	public static final String DEFAULT_IMAGE_MODEL = OpenAiImageApi.ImageModel.GPT_IMAGE_1_MINI.getValue();
 
 	/**
 	 * Options for OpenAI Image API.

models/spring-ai-openai/src/main/java/org/springframework/ai/openai/OpenAiImageOptions.java

@@ -67,27 +67,31 @@ public class OpenAiImageOptions implements ImageOptions {
 	private Integer height;
 
 	/**
-	 * The quality of the image that will be generated. hd creates images with finer
-	 * details and greater consistency across the image. This param is only supported for
-	 * dall-e-3.
+	 * The quality of the image that will be generated. auto (default value) will
+	 * automatically select the best quality for the given model. high, medium and low are
+	 * supported for gpt-image-1. hd and standard are supported for dall-e-3. standard is
+	 * the only option for dall-e-2.
 	 */
 	@JsonProperty("quality")
 	private String quality;
 
 	/**
-	 * The format in which the generated images are returned. Must be one of url or
-	 * b64_json.
+	 * The format in which generated images with dall-e-2 and dall-e-3 are returned. Must
+	 * be one of url or b64_json. URLs are only valid for 60 minutes after the image has
+	 * been generated. This parameter isn't supported for gpt-image-1 which will always
+	 * return base64-encoded images.
 	 */
 	@JsonProperty("response_format")
 	private String responseFormat;
 
 	/**
-	 * The size of the generated images. Must be one of 256x256, 512x512, or 1024x1024 for
-	 * dall-e-2. Must be one of 1024x1024, 1792x1024, or 1024x1792 for dall-e-3 models.
-	 * This property is automatically computed when both width and height are set,
-	 * following the format "widthxheight". When setting this property directly, it must
-	 * follow the format "WxH" where W and H are valid integers. Invalid formats will
-	 * result in null width and height values.
+	 * The size of the generated images. Must be one of 1024x1024, 1536x1024 (landscape),
+	 * 1024x1536 (portrait), or auto (default value) for gpt-image-1. Must be one of
+	 * 256x256, 512x512, or 1024x1024 for dall-e-2. Must be one of 1024x1024, 1792x1024,
+	 * or 1024x1792 for dall-e-3. This property is automatically computed when both width
+	 * and height are set, following the format "widthxheight". When setting this property
+	 * directly, it must follow the format "WxH" where W and H are valid integers. Invalid
+	 * formats will result in null width and height values.
 	 */
 	@JsonProperty("size")
 	private String size;
@@ -108,6 +112,52 @@ public class OpenAiImageOptions implements ImageOptions {
 	@JsonProperty("user")
 	private String user;
 
+	/**
+	 * Allows to set transparency for the background of the generated image(s). This
+	 * parameter is only supported for gpt-image-1. Must be one of transparent, opaque or
+	 * auto (default value). When auto is used, the model will automatically determine the
+	 * best background for the image.
+	 */
+	@JsonProperty("background")
+	private String background;
+
+	/**
+	 * Control the content-moderation level for images generated by gpt-image-1. Must be
+	 * either low for less restrictive filtering or auto (default value).
+	 */
+	@JsonProperty("moderation")
+	private String moderation;
+
+	/**
+	 * The compression level (0-100%) for the generated images. This parameter is only
+	 * supported for gpt-image-1 with the webp or jpeg output formats, and defaults to
+	 * 100.
+	 */
+	@JsonProperty("output_compression")
+	private Integer outputCompression;
+
+	/**
+	 * The format in which the generated images are returned. This parameter is only
+	 * supported for gpt-image-1. Must be one of png, jpeg, or webp.
+	 */
+	@JsonProperty("output_format")
+	private String outputFormat;
+
+	/**
+	 * The number of partial images to generate. This parameter is used for streaming
+	 * responses that return partial images. Value must be between 0 and 3. When set to 0,
+	 * the response will be a single image sent in one streaming event.
+	 */
+	@JsonProperty("partial_images")
+	private Integer partialImages;
+
+	/**
+	 * Generate the image in streaming mode. Defaults to false. This parameter is only
+	 * supported for gpt-image-1.
+	 */
+	@JsonProperty("stream")
+	private Boolean stream;
+
 	public static Builder builder() {
 		return new Builder();
 	}
@@ -128,6 +178,12 @@ public static OpenAiImageOptions fromOptions(OpenAiImageOptions fromOptions) {
 		options.size = fromOptions.size;
 		options.style = fromOptions.style;
 		options.user = fromOptions.user;
+		options.background = fromOptions.background;
+		options.moderation = fromOptions.moderation;
+		options.outputCompression = fromOptions.outputCompression;
+		options.outputFormat = fromOptions.outputFormat;
+		options.partialImages = fromOptions.partialImages;
+		options.stream = fromOptions.stream;
 		return options;
 	}
 
@@ -262,6 +318,54 @@ public void setSize(String size) {
 		}
 	}
 
+	public String getBackground() {
+		return this.background;
+	}
+
+	public void setBackground(String background) {
+		this.background = background;
+	}
+
+	public String getModeration() {
+		return this.moderation;
+	}
+
+	public void setModeration(String moderation) {
+		this.moderation = moderation;
+	}
+
+	public Integer getOutputCompression() {
+		return this.outputCompression;
+	}
+
+	public void setOutputCompression(Integer outputCompression) {
+		this.outputCompression = outputCompression;
+	}
+
+	public String getOutputFormat() {
+		return this.outputFormat;
+	}
+
+	public void setOutputFormat(String outputFormat) {
+		this.outputFormat = outputFormat;
+	}
+
+	public Integer getPartialImages() {
+		return this.partialImages;
+	}
+
+	public void setPartialImages(Integer partialImages) {
+		this.partialImages = partialImages;
+	}
+
+	public Boolean getStream() {
+		return this.stream;
+	}
+
+	public void setStream(Boolean stream) {
+		this.stream = stream;
+	}
+
 	@Override
 	public boolean equals(Object o) {
 		if (this == o) {
@@ -274,21 +378,28 @@ public boolean equals(Object o) {
 				&& Objects.equals(this.width, that.width) && Objects.equals(this.height, that.height)
 				&& Objects.equals(this.quality, that.quality)
 				&& Objects.equals(this.responseFormat, that.responseFormat) && Objects.equals(this.size, that.size)
-				&& Objects.equals(this.style, that.style) && Objects.equals(this.user, that.user);
+				&& Objects.equals(this.style, that.style) && Objects.equals(this.user, that.user)
+				&& Objects.equals(this.background, that.background) && Objects.equals(this.moderation, that.moderation)
+				&& Objects.equals(this.outputCompression, that.outputCompression)
+				&& Objects.equals(this.outputFormat, that.outputFormat)
+				&& Objects.equals(this.partialImages, that.partialImages) && Objects.equals(this.stream, that.stream);
 	}
 
 	@Override
 	public int hashCode() {
 		return Objects.hash(this.n, this.model, this.width, this.height, this.quality, this.responseFormat, this.size,
-				this.style, this.user);
+				this.style, this.user, this.background, this.moderation, this.outputCompression, this.outputFormat,
+				this.partialImages, this.stream);
 	}
 
 	@Override
 	public String toString() {
 		return "OpenAiImageOptions{" + "n=" + this.n + ", model='" + this.model + '\'' + ", width=" + this.width
 				+ ", height=" + this.height + ", quality='" + this.quality + '\'' + ", responseFormat='"
 				+ this.responseFormat + '\'' + ", size='" + this.size + '\'' + ", style='" + this.style + '\''
-				+ ", user='" + this.user + '\'' + '}';
+				+ ", user='" + this.user + '\'' + ", background='" + this.background + '\'' + ", moderation='"
+				+ this.moderation + '\'' + ", outputCompression=" + this.outputCompression + ", outputFormat='"
+				+ this.outputFormat + '\'' + ", partialImages=" + this.partialImages + ", stream=" + this.stream + '}';
 	}
 
 	/**
@@ -351,6 +462,36 @@ public Builder user(String user) {
 			return this;
 		}
 
+		public Builder background(String background) {
+			this.options.setBackground(background);
+			return this;
+		}
+
+		public Builder moderation(String moderation) {
+			this.options.setModeration(moderation);
+			return this;
+		}
+
+		public Builder outputCompression(Integer outputCompression) {
+			this.options.setOutputCompression(outputCompression);
+			return this;
+		}
+
+		public Builder outputFormat(String outputFormat) {
+			this.options.setOutputFormat(outputFormat);
+			return this;
+		}
+
+		public Builder partialImages(Integer partialImages) {
+			this.options.setPartialImages(partialImages);
+			return this;
+		}
+
+		public Builder stream(Boolean stream) {
+			this.options.setStream(stream);
+			return this;
+		}
+
 		public OpenAiImageOptions build() {
 			return this.options;
 		}

models/spring-ai-openai/src/main/java/org/springframework/ai/openai/api/OpenAiImageApi.java

@@ -45,7 +45,7 @@
  */
 public class OpenAiImageApi {
 
-	public static final String DEFAULT_IMAGE_MODEL = ImageModel.DALL_E_3.getValue();
+	public static final String DEFAULT_IMAGE_MODEL = ImageModel.GPT_IMAGE_1_MINI.getValue();
 
 	private final RestClient restClient;
 
@@ -99,10 +99,22 @@ public static Builder builder() {
 
 	/**
 	 * OpenAI Image API model.
-	 * <a href="https://platform.openai.com/docs/models/dall-e">DALL·E</a>
+	 * <a href="https://platform.openai.com/docs/models">Models</a>
 	 */
 	public enum ImageModel {
 
+		/**
+		 * Multimodal language model that accepts both text and image inputs, and produces
+		 * image outputs.
+		 */
+		GPT_IMAGE_1("gpt-image-1"),
+
+		/**
+		 * A cost-efficient version of GPT Image 1. It is a natively multimodal language
+		 * model that accepts both text and image inputs, and produces image outputs.
+		 */
+		GPT_IMAGE_1_MINI("gpt-image-1-mini"),
+
 		/**
 		 * The latest DALL·E model released in Nov 2023.
 		 */
@@ -137,10 +149,16 @@ public record OpenAiImageRequest(
 		@JsonProperty("response_format") String responseFormat,
 		@JsonProperty("size") String size,
 		@JsonProperty("style") String style,
-		@JsonProperty("user") String user) {
+		@JsonProperty("user") String user,
+		@JsonProperty("background") String background,
+		@JsonProperty("moderation") String moderation,
+		@JsonProperty("output_compression") Integer outputCompression,
+		@JsonProperty("output_format") String outputFormat,
+		@JsonProperty("partial_images") Integer partialImages,
+		@JsonProperty("stream") Boolean stream) {
 
 		public OpenAiImageRequest(String prompt, String model) {
-			this(prompt, model, null, null, null, null, null, null);
+			this(prompt, model, null, null, null, null, null, null, null, null, null, null, null, null);
 		}
 	}