562991 砍、發明說明 (發明說明應敘明：發明所屬之技術領域、先前技術、內容、實施方式及圖式簡單說 明） 發明所屬之技術領域 本發明是有關於一種曝光値（exposure value，簡稱EV)的 收斂方法，且特別是有關於一種利用建立的曝光値表之適當 曝光値之快速收斂方法。 先前技術 在數位攝影裝置中，如果以l〇24x 768個畫素來拍攝影 像，並且每一個畫素的亮度範圍爲〇至255，則所拍攝到的影 像平均亮度如何能快速地收敛’便成爲目則急需解決的問題。 習知之一種方法請參照中華民國專利公告號234748之 「數位靜態電子照相機之模糊控制自動曝光系統」，此習知 方法是利用模糊控制的方式’使所拍攝到的影像能維持適當 的亮度。然而，由於模糊控制法則相當繁瑣且複雜，必須有 經驗的專業人員才能適當地修改模糊控制法則，因此這種習 知方法的模糊控制法則相當不容易修改。再者，由於軟體程 式必須依照繁瑣且複雜的模糊控制法則，才能得出維持影像 適當亮度的評價値’所以自動曝光的收斂速度太慢且耗費大 量計算資源。 發明內霞 有鑑於此，本發明提出一種適當曝光値之快速收斂方法。 本發明長藉由建立修改方式相當簡單的曝光値表，而使數位 攝影裝虞中的光學感測器所擷取到的影像在閉迴路運算中， 快速收斂到適當曝光値，因此本發明不但可以輕易達成多變 10046twf 5 562991 數（曝光時間、增益値、以及光圏大小）的曝光控制，而且能快 速收斂到適當的自動曝光値。 爲達成上述及其他目的，本發明提出一種適當曝光値之 快速收斂方法。此快速收斂方法適用於數位攝影裝置。此快 速收斂方法包括下列步驟：（a)根據此數位攝影機而建立曝光 値表，此曝光値表包括數個曝光値、數個曝光時間、數個增 益値、以及數個光圈大小，其中曝光値係曝光時間、增益値、 以及光圈大小之函數；（b)定義自動曝光收斂區間，此自動曝 光收斂區間的中心點係目標亮度；（c)從曝光値表的曝光値中 選擇一先前曝光値做爲初始化設定；（d)經由此數位攝影裝置 中的光學感測器擷取一影像，並且將此影像分成數個子區域； (e)將每一個子區域的子區域影像平均亮度乘以對應的影像加 權値後，除以總影像加權値，而得出平均亮度；（f)依據此先 前曝光値及近似函數而得出一預測曝光値，其中近似函數係 目標亮度及平均亮度的函數；以及（g)當此預測曝光値與此先 前曝光値相等時，則自動曝光爲收斂而完成自動曝光，並以 此預測曝光値當作適當曝光値。另外，當此預測曝光値與此 先前曝光値不相等時，會以此預測曝光値當作此先前曝光値， 並經由查詢曝光値表而得出對應的曝光時間、增益値、以及 光圈大小，然後會重複執行步驟（d)、（e)、（f)、以及（g)，直到 自動收斂爲止。 在本發明的較佳實施例中，曝光値表可以調整。 在本發明的較佳實施例中，曝光値表的最小間隔係曝光 値解析度，並且曝光値解析度可以調整。 在本發明的較佳實施例中，自動曝光收斂區間的大小係 與曝光値解析度成比例。 6 10046twf 562991 在本發明的較佳實施例中，自動曝光收斂區間的大小係 與曝光値解析度相等。或者是自動曝光收斂區間係介於目標 売度除以2的一半曝光値解析度次方與目標亮度乘以2的一 半曝光値解析度次方之間。 在本發明的較佳實施例中，預測曝光値係此先前曝光値 減去近似函數。 在本發明的較佳實施例中，光學感測器可爲電荷耦合元 件（charge coupled device，簡稱CCD)或互補式金氧半導體 (complementary metal oxide semiconductor ，簡稱 CMOS)元 件。 綜上所述，本發明是藉由建立修改方式相當簡單的曝光値 表’而使數位攝影裝置中的光學感測器所擷取到的影像在閉 迴路運算中，快速收斂到適當曝光値，因此本發明不但可以 輕易達成多變數（曝光時間、增益値、以及光圈大,』、）的曝光控 制’而且能快速收斂到適當的自動曝光値。 爲讓本發明之上述和其他目的、特徵和優點，能更加明顯 易懂，下文特舉較佳實施例，並配合所附圖示，做詳細說明 如下： 實施方式： 請參照第1圖’其繪示的是根據本發明一較佳實施例之 適當曝光値之快速收斂方法的流程圖。由第丨圖可知，此快 速收斂方法首先需依據數位攝影裝置（例如是數位相機或數位 攝影機）的規格而建立曝光値（eXp0sure value，簡稱EV)表（如 步驟S102)。在曝光値表中，包括數個曝光値、數個曝光時間 (以ExP-1表示）、數個增益値(以AGC表示）、以及數個光圈大 小(以F—no表示）。其中，曝光値爲曝光時間、增益値、以及 10046twf 7 562991 光圈大小之函數’亦即曝光値與曝光時間、增益値、以及光 圈大小之間的關係需符合以下的式（1) · = 2 log 2 (芦一⑽)-i〇g2 (脚」)- i〇g2 W α /1 〇〇)…⑴ 而根據本發明一較佳實施例之曝光値表’請參照第2圖所繪 示。由第2圖可知，此曝光値表包括曝光値202、曝光時間204、 增益値206、以及光圈大小208。其中，以本實施例而言，曝 光値202係介於4與16之間，並且將曝光値區分成在大太陽 的曝光値、在陰天的曝光値、在黃昏/日出的曝光値、以及在 星光下的曝光値四大部分；本實施例之曝光時間204係介於 1/10〇〇秒與1/15秒之間；本實施例之增益値206係介於1〇〇 與800之間；而本實施例之光圈大小208係介於F2.8與F8之 間。爲了證明此曝光値表符合式（1)，特以一例來作說明。由 第2圖可知，在曝光値爲爲15時，所對應的曝光時間、增益 値、以及光圈大小分別爲1/500秒、F8、以及100，然後將這 些値 帶入式 （1) 可得 五F = 21og2(8)-l〇g2(l/500)-l〇g2(l〇〇/1〇〇)=6 + 9=1 5,所以符合式（1)。 因此，對於熟習者而言，應了解到的是，第2圖中的查詢表 並非用以限定本發明，只要需符合式（1)而建立查詢表都可以 爲之。再者’由第2圖可知，此曝光値表的最小間隔爲0.5， 亦即此曝光値表的曝光値解析度（EV Resolution)爲0.5。而曝 光値解析度可以依據使用者的需求及數位攝影裝置的規格而 做調整。 接著，會定義自動曝光收斂區間（如步驟S104)，此自動 曝光收斂區間的中心點係目標亮度（Target γ)，此目標亮度可 由使用者設定。在一較佳實施例中，自動曝光收斂區間的大 小係設定爲與曝光値解析度相等。或者是自動曝光收斂區間 10046twf 8 562991 係介於目標亮度除以2的一半曝光値解析度次方與目標亮度 乘以2的一半曝光値解析度次方之間，亦即自動曝光收斂區 EV Re solution EV Re solution 間爲 Windows((Target Yx2 '~~ )，（Target Yx2 ~~~'))， 舉例而H，Target Y=100，EV Resolution=0.5，則落於 84.09 與118.92之間的亮度均視之爲自動曝光收斂。 接著’會從曝光値表的曝光値中選擇一先前曝光値 (Previous EV)(如步驟 S106)。 接著，會經由此數位攝影裝置中的光學感測器（例如是電 荷耦合元件（CCD)或互補式金氧半導體（CMOS)元件）擷取一影 像，並且將此影像分成數個子區域（如步驟S108)，然後將每 一個子區域的子區域影像平均亮度（Y)乘以對應的影像加權値 (W)後，除以總影像加權値，而得出此影像各個畫素的平均亮 度（Yavg)(如步驟S110)。爲了更淸楚起見，請參照第3圖， 其繪示的是根據本發明一較佳實施之所擷取的影像及影像加 權値。由第3圖可知，所擷取的影像32係分割成9 X 11個 子區域，其中每個子區域的子區域平均影像亮度爲Y。而影像 加權値34亦分割成9 X 11個子區域，其中每個子區域的影 像加權値爲W。然後，經由以下的式(2): 10 8 ΣΣΥ^ν ㈣~~…(2) ΣΣ% 7=0/=0 . ’可得知此影像各個畫素的平均亮度（Ywg)。 接著，會依據此先前曝光値及近似函數而得出一預測曝 光値（Predict EV)，其中近似函數（truncate)係目標亮度（Target Y) 及平均亮度（Yavg)的函數(如步驟S112)。在一較佳實施例中， 此預測曝光値係此先前曝光値減去近似函數，亦即此預測曝 10046twf 9 562991 光値與此先前曝光値及近似函數之間的關係需符合以下的式 (3):562991 Description of the invention (The description of the invention should state: the technical field to which the invention belongs, the prior art, the content, the embodiments, and the drawings are briefly explained) The technical field to which the invention belongs The invention relates to an exposure value (EV) ), And in particular, it relates to a fast convergence method that uses the appropriate exposure of the established exposure table. In the prior art, in a digital photography device, if an image is captured with 1024x768 pixels, and the brightness range of each pixel is 0 to 255, how can the average brightness of the captured image quickly converge? Urgent problems need to be solved. For a known method, please refer to the "Fuzzy Control Automatic Exposure System for Digital Still Electronic Cameras" of the Republic of China Patent Publication No. 234748. This conventional method is to use the method of fuzzy control to make the captured image maintain proper brightness. However, since the fuzzy control law is quite cumbersome and complicated, it is necessary for an experienced professional to properly modify the fuzzy control law, so the fuzzy control law of this conventional method is quite difficult to modify. Furthermore, because the software program must follow the complicated and complicated fuzzy control rules to obtain an evaluation to maintain the proper brightness of the image 値 ’, the convergence rate of automatic exposure is too slow and consumes a large amount of computing resources. In view of this, the present invention proposes a fast convergence method for proper exposure. In the present invention, by establishing a relatively simple exposure meter in a modified manner, the image captured by the optical sensor in the digital photography equipment quickly converges to an appropriate exposure rate in a closed-loop operation. Therefore, the present invention not only It can easily achieve variable control of 10046twf 5 562991 numbers (exposure time, gain value, and light size), and can quickly converge to the appropriate automatic exposure value. To achieve the above and other objectives, the present invention proposes a fast convergence method with proper exposure. This fast convergence method is suitable for digital photography devices. The fast convergence method includes the following steps: (a) establishing an exposure meter according to the digital camera, the exposure meter includes a plurality of exposures, a plurality of exposure times, a plurality of gains, and a plurality of aperture sizes, wherein the exposures are Is a function of exposure time, gain 値, and aperture size; (b) defines the auto-exposure convergence interval, and the center point of this auto-exposure convergence interval is the target brightness; (c) selects a previous exposure from the exposures in the exposure table 値As initial settings; (d) capturing an image through the optical sensor in the digital camera, and dividing the image into several sub-regions; (e) multiplying the average brightness of the sub-region image of each sub-region by the corresponding After dividing the weighted image, the average brightness is obtained by dividing by the total image weight; (f) a predicted exposure is obtained based on the previous exposure and the approximate function, where the approximate function is a function of the target brightness and the average brightness; And (g) when the predicted exposure 値 is equal to the previous exposure ，, the automatic exposure completes the automatic exposure to converge, and uses this predicted exposure 値 as a suitable When exposed 値. In addition, when the predicted exposure 値 is not equal to the previous exposure ，, the predicted exposure 値 is used as the previous exposure 値, and the corresponding exposure time, gain 値, and aperture size are obtained by querying the exposure table, Steps (d), (e), (f), and (g) are then repeated until it converges automatically. In a preferred embodiment of the invention, the exposure profile can be adjusted. In a preferred embodiment of the present invention, the minimum interval of the exposure meter is the exposure rate resolution, and the exposure rate resolution can be adjusted. In a preferred embodiment of the present invention, the size of the automatic exposure convergence interval is proportional to the exposure frame resolution. 6 10046twf 562991 In a preferred embodiment of the present invention, the size of the auto-exposure convergence interval is equal to the exposure frame resolution. Or the auto-exposure convergence interval is between the target power divided by half of the exposure 値 resolution power and the target brightness multiplied by half the exposure 値 resolution power. In a preferred embodiment of the invention, the predicted exposure is the previous exposure minus the approximate function. In a preferred embodiment of the present invention, the optical sensor may be a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) device. In summary, the present invention is to quickly converge the image captured by the optical sensor in the digital photography device to an appropriate exposure in a closed-loop operation by establishing an exposure meter that is relatively simple to modify. Therefore, the present invention can not only easily achieve exposure control of multiple variables (exposure time, gain 値, and large aperture, ″,), but also quickly converge to an appropriate automatic exposure 値. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments in detail with the accompanying drawings as follows: Implementation: Please refer to FIG. Illustrated is a flowchart of a fast convergence method for a proper exposure method according to a preferred embodiment of the present invention. It can be seen from FIG. 丨 that the fast convergence method firstly needs to establish an eXp0sure value (EV) table according to the specifications of a digital camera (such as a digital camera or a digital camera) (eg, step S102). The exposure chart includes several exposures, several exposure times (expressed as ExP-1), several gains (expressed as AGC), and several aperture sizes (expressed as F-no). Among them, exposure 値 is a function of exposure time, gain 値, and 10046twf 7 562991 aperture size ', that is, the relationship between exposure 値 and exposure time, gain 値, and aperture size must meet the following formula (1) · = 2 log 2 (芦 一 ⑽) -i〇g2 (foot))-i〇g2 W α / 1 00) ... and the exposure table according to a preferred embodiment of the present invention is shown in FIG. 2. It can be seen from FIG. 2 that the exposure chart includes an exposure table 202, an exposure time 204, a gain table 206, and an aperture size 208. Among them, according to this embodiment, the exposure 値 202 is between 4 and 16, and the exposure 値 is divided into exposure on a big sun 値, exposure on a cloudy day 値, exposure on dusk / sunrise 値, And four major parts of exposure under starlight; the exposure time 204 of this embodiment is between 1 / 10th of a second and 1 / 15th of a second; the gain 206 of this embodiment is between 100 and 800 The iris size 208 of this embodiment is between F2.8 and F8. In order to prove that the exposure meter conforms to the formula (1), an example is used for explanation. From Figure 2, it can be seen that when the exposure angle is 15, the corresponding exposure time, gain, and aperture size are 1/500 second, F8, and 100, respectively, and then bring these angles into equation (1) to obtain Five F = 21og2 (8) -l0g2 (l / 500) -l0g2 (lOO / 1100) = 6 + 9 = 1 5, so it is consistent with formula (1). Therefore, for those skilled in the art, it should be understood that the look-up table in FIG. 2 is not used to limit the present invention, as long as the look-up table needs to conform to the formula (1), it can be done. Furthermore, it can be seen from FIG. 2 that the minimum interval of the exposure meter is 0.5, that is, the exposure resolution of the exposure meter is 0.5. The exposure resolution can be adjusted according to the needs of the user and the specifications of the digital camera. Next, an automatic exposure convergence interval is defined (eg, step S104). The center point of this automatic exposure convergence interval is the target brightness (Target γ). This target brightness can be set by the user. In a preferred embodiment, the size of the auto-exposure convergence interval is set equal to the exposure frame resolution. Or the auto-exposure convergence interval 10046twf 8 562991 is between the target brightness divided by half of the exposure 値 resolution power and the target brightness multiplied by half of the exposure 値 resolution power, that is, the auto exposure convergence area EV Re The solution EV Re solution is Windows ((Target Yx2 '~~), (Target Yx2 ~~~')). For example, H, Target Y = 100, and EV Resolution = 0.5, then the brightness falls between 84.09 and 118.92. Both regard it as auto exposure convergence. Next, a previous exposure (Previous EV) is selected from the exposure list of the exposure list (step S106). Then, an image is captured by an optical sensor (such as a charge-coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) device) in the digital photographing device, and the image is divided into several sub-areas (such as steps S108), and then multiply the average image brightness (Y) of the sub-region image of each sub-region by the corresponding image weight 値 (W), and divide by the total image weight 値 to obtain the average brightness of each pixel of this image (Yavg ) (As in step S110). For better understanding, please refer to FIG. 3, which shows the captured image and image weighting according to a preferred implementation of the present invention. As can be seen from Figure 3, the captured image 32 is divided into 9 X 11 sub-regions, and the average image brightness of each sub-region is Y. The image weighting 値 34 is also divided into 9 × 11 sub-regions, where the image weighting 每个 of each sub-region is W. Then, through the following formula (2): 10 8 ΣΣΥ ^ ν ㈣ ~~ (2) ΣΣ% 7 = 0 / = 0. ′, The average brightness (Ywg) of each pixel of this image can be obtained. Next, a predicted exposure (Predict EV) is obtained based on the previous exposure and the approximate function, where the approximate function (truncate) is a function of the target brightness (Target Y) and the average brightness (Yavg) (eg, step S112). In a preferred embodiment, the predicted exposure is the previous exposure minus the approximate function, that is, the relationship between the predicted exposure and the previous exposure and the approximate function needs to be in accordance with the following formula ( 3):
Predict EV = Previous EV-truncate(log2(^^^g^))...(3)Predict EV = Previous EV-truncate (log2 (^^^ g ^)) ... (3)
Yavg 爲了能更了解近似函數，將以下列的例子做說明。當曝光値 表的曝光解析度〇·5時，如果近似函數爲truncate(4.4)，則 truncate(4.4)=4.5 ;而如果近似函數爲 truncate(4.1)，則 truncate(4.1)=4。由此可知，近似函數係取決於曝光解析度的 大小。 接下來，會判斷此預測曝光値是否此先前曝光値相等（如 步驟S114)。如果此預測曝光値與此先前曝光値相等，則自動 曝光會判斷爲收斂而完成自動曝光，並以此預測曝光値當作 適當曝光値（如步驟S116)。爲了更淸楚起見，將以配合第2 圖的一例做說明。如果目標亮度爲100，由第2圖的曝光値表 中所選擇的先前曝光値爲12,所擷取的影像之平均亮度爲 105 ， 由於預測曝光値 Predict EV=12- truncate(log2(100/105))=12-0=12=先前曝光値，所以自動曝光 會判斷爲收斂而完成自動曝光，並以預測曝光値12當作適當 曝光値。 而如果此預測曝光値與此先前曝光値不相等，則會以此 預測曝光値當作此先前曝光値，並經由查詢曝光値表而得出 對應的曝光時間、增益値、以及光圈大小，然後會重複執行 步驟S108至步驟S114,直到自動收斂爲止。爲了更淸楚起見， 將以配合第2圖的一例做說明。如果目標亮度爲10〇，由第2 圖的曝光値表中所選擇的先前曝光値爲16,所擷取的影像之 平均亮度爲5，則預測曝光値=16-truncate(l〇g2(100/5))==16_ 4.5 = 11.5。由於預測曝光値11.5並不等於先前曝光値16，所 10046tvvf 10 562991 以會以11.5當作先前曝光値。接著，查詢第2圖中的曝光値 表可知’曝光値爲11.5所對應的曝光時間、增益値、以及光 圈大小分別爲1/250秒、141、以及F2.8，然後以這些參數値 來設定數位攝影裝置，並且再擷取一影像。接著，計算出此 影像的平均亮度爲150，然後可得出預測曝光値=11.5-truncate(log2(100/150))=1 1.5 + 0.5 = 12。由於預測曝光値 12 還 是不等於先前曝光値11.5，所以會以12當作先前曝光値。接 著，查詢第2圖中的曝光値表可知，曝光値爲12所對應的曝 光時間、增益値、以及光圈大小分別爲1/250秒、100、以及 F4，然後以這些參數値來設定數位攝影裝置，並且再擷取一 影像。接下來，計算出此影像的平均亮度爲105，然後可得出 預測曝光値=12-truncate(log2(100/105))=12-0=12。此時可得 知，由於預測曝光値12已經與先前曝光値12相等，所以自 動曝光會判斷爲收斂而完成自動曝光，並以此時的預測曝光 値12當作適當曝光値。 綜上所述，本發明是藉由建立修改方式相當簡單的曝光 値表，而使數位攝影裝置中的光學感測器所擷取到的影像在 閉迴路運算中，快速收斂到適當曝光値，因此本發明不但可 以輕易達成多變數（曝光時間、增益値、以及光圈大小）的曝光 控制，而且能快速收斂到適當的自動曝光値。 雖然本發明已以較佳實施例揭露於上，然其並非用以限 定本發明，任何熟習此技藝者，在不脫離本發明之精神和範 圍內，當可作各種之更動與潤飾，因此本發明之保護範圍當 視後附之申請專利範圍所介定者爲準。 10046twf 562991 圖式簡單說明= 第1圖繪示的是根據本發明一較佳實施例之適當曝光値 之快速收斂方法的流程圖； 第2圖繪示的是根據本發明一較佳實施例之曝光値表；以 及 第3圖繪示的是根據本發明一較佳實施之所擷取的影像及 影像加權値。 圖式標示說明= 202 :曝光値 204 :曝光時間 206 :增益値 208 :光圈大小 32 :所擷取的影像 34 :影像加權値 S102-S118 :本發明一較佳實施例之施行步驟 10046twf 12In order to better understand the approximate function, Yavg will use the following example to illustrate. When the exposure resolution of the exposure table is 0.5, if the approximate function is truncate (4.4), then truncate (4.4) = 4.5; and if the approximate function is truncate (4.1), then truncate (4.1) = 4. This shows that the approximate function depends on the size of the exposure resolution. Next, it is judged whether the predicted exposure is equal to the previous exposure (step S114). If the predicted exposure 値 is equal to the previous exposure 値, the automatic exposure is judged to be convergent and the automatic exposure is completed, and the predicted exposure 値 is regarded as an appropriate exposure 如 (step S116). For the sake of clarity, an example in conjunction with Figure 2 will be described. If the target brightness is 100, the previous exposure selected in the exposure chart in Figure 2 is 12, and the average brightness of the captured image is 105. Since the predicted exposure is Predict EV = 12- truncate (log2 (100 / 105)) = 12-0 = 12 = previous exposure 値, so the automatic exposure will be judged to be convergent and complete the automatic exposure, and the predicted exposure 値 12 will be used as the appropriate exposure 値. If the predicted exposure is not equal to the previous exposure, the predicted exposure will be used as the previous exposure, and the corresponding exposure time, gain, and aperture size will be obtained by querying the exposure table, and then Steps S108 to S114 will be repeatedly performed until it automatically converges. For the sake of clarity, an example in conjunction with FIG. 2 will be described. If the target brightness is 10, the previous exposure selected from the exposure chart in Figure 2 is 16, and the average brightness of the captured image is 5, then the predicted exposure is 値 = 16-truncate (l0g2 (100 / 5)) == 16_ 4.5 = 11.5. Since the predicted exposure (11.5) is not equal to the previous exposure (16), 10046tvvf 10 562991 will use 11.5 as the previous exposure. Next, query the exposure time table in Figure 2 to know that the exposure time, gain value, and aperture size corresponding to 'exposure' is 11.5 are 1/250 seconds, 141, and F2.8, and then set with these parameters. Digital camera and capture another image. Then, the average brightness of this image is calculated as 150, and then the predicted exposure 値 = 11.5-truncate (log2 (100/150)) = 1 1.5 + 0.5 = 12 can be obtained. Since the predicted exposure 値 12 is not equal to the previous exposure 値 11.5, 12 is taken as the previous exposure 値. Next, querying the exposure chart in Figure 2 shows that the exposure time is 12, the exposure time, gain, and aperture size are 1/250 seconds, 100, and F4, and then use these parameters to set digital photography. Device, and capture another image. Next, calculate the average brightness of this image to be 105, and then get the predicted exposure 値 = 12-truncate (log2 (100/105)) = 12-0 = 12. At this time, it can be known that since the predicted exposure 値 12 is already equal to the previous exposure 値 12, the automatic exposure will be judged to be convergent to complete the automatic exposure, and the predicted exposure 値 12 at this time is regarded as an appropriate exposure 値. In summary, the present invention is to quickly converge the image captured by the optical sensor in the digital photography device to a proper exposure in a closed-loop operation by establishing an exposure meter with a relatively simple modification method. Therefore, the present invention can not only easily achieve exposure control of multiple variables (exposure time, gain 値, and aperture size), but also quickly converge to an appropriate automatic exposure 値. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and retouches without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application. 10046twf 562991 Brief description of the diagram = Fig. 1 shows a flowchart of a fast convergence method for proper exposure according to a preferred embodiment of the present invention; Fig. 2 shows a flowchart of a fast convergence method according to a preferred embodiment of the present invention The exposure chart; and FIG. 3 shows the captured image and image weighting chart according to a preferred implementation of the present invention. Graphical description = 202: exposure 値 204: exposure time 206: gain 値 208: aperture size 32: captured image 34: image weighting S102-S118: implementation steps of a preferred embodiment of the present invention 10046twf 12